2021-07-22 00:49:52

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 00/25] LSM: Module stacking for AppArmor

This patchset provides the changes required for
the AppArmor security module to stack safely with any other.

v28: Rebase to 5.14-rc2
Provide IMA rules bounds checking (patch 04)
Quote contexts in MAC_TASK_CONTEXTS and MAC_OBJ_CONTEXTS
audit records because of AppArmor's use of '=' in context
values. (patch 22,23)
v27: Fixes for landlock (patch 02)
Rework the subject audit record generation. This version is
simpler and reflects feedback from Paul Moore. (patch 22)
v26: Rebase to 5.13-rc1
Include the landlock security module.
Accomodate change from security_task_getsecid() to
security_task_getsecid_obj() and security_task_getsecid_subj().
v25: Rebase to 5.12-rc2
Incorporate feedback from v24
- The IMA team suggested improvements to the integrity rule
processing.
v24: Rebase to 5.11-rc1
Incorporate feedback from v23
- Address the IMA team's concerns about "label collisions".
A label collision occurs when there is ambiguity about
which of multiple LSMs is being targeted in the definition
of an integrity check rule. A system with Smack and
AppArmor would be unable to distinguish which LSM is
important to an integrity rule referrencing the label
"unconfined" as that label is meaningful to both.
Provide a boot option to specify which LSM will be used in
IMA rules when multiple LSMs are present. (patch 04)
Pull LSM "slot" identification from later audit patches in
in support of this (patch 03).
- Pick up a few audit events that need to include supplimental
subject context records that had been missed in the
previous version.
v23: Rebase to 5.10-rc4
Incorporate feedback from v22
- Change /proc/*/attr/display to /proc/*/attr/interface_lsm to
make the purpose clearer. (patch 0012)
- Include ABI documentation. (patch 0012, 0022)
- Introduce LSM documentation updates with the patches where
the interfaces are added rather than at the end. (patch 0012, 0022)
Include more maintainers and mail lists in To: and Cc: directives.
v22: Rebase to 5.10-rc1
v21: Rebase to 5.9-rc4
Incorporate feedback from v20
- Further revert UDS SO_PEERSEC to use scaffolding around
the interfaces that use lsmblobs and store only a single
secid. The possibility of multiple security modules
requiring data here is still a future problem.
- Incorporate Richard Guy Briggs' non-syscall auxiliary
records patch (patch 0019-0021) in place of my "supplimental"
records implementation. [I'm not sure I've given proper
attestation. I will correct as appropriate]
v20: Rebase to 5.9-rc1
Change the BPF security module to use the lsmblob data. (patch 0002)
Repair length logic in subject label processing (patch 0015)
Handle -EINVAL from the empty BPF setprocattr hook (patch 0020)
Correct length processing in append_ctx() (patch 0022)
v19: Rebase to 5.8-rc6
Incorporate feedback from v18
- Revert UDS SO_PEERSEC implementation to use lsmblobs
directly, rather than allocating as needed. The correct
treatment of out-of-memory conditions in the later case
is difficult to define. (patch 0005)
- Use a size_t in append_ctx() (patch 0021)
- Fix a memory leak when creating compound contexts. (patch 0021)
Fix build error when CONFIG_SECURITY isn't set (patch 0013)
Fix build error when CONFIG_SECURITY isn't set (patch 0020)
Fix build error when CONFIG_SECURITY isn't set (patch 0021)
v18: Rebase to 5.8-rc3
Incorporate feedback from v17
- Null pointer checking in UDS (patch 0005)
Match changes in IMA code (patch 0012)
Fix the behavior of LSM context supplimental audit
records so that there's always exactly one when it's
appropriate for there to be one. This is a substantial
change that requires extention of the audit_context beyond
syscall events. (patch 0020)
v17: Rebase to 5.7-rc4
v16: Rebase to 5.6
Incorporate feedback from v15 - Thanks Stephen, Mimi and Paul
- Generally improve commit messages WRT scaffolding
- Comment ima_lsm_isset() (patch 0002)
- Some question may remain on IMA warning (patch 0002)
- Mark lsm_slot as __lsm_ro_after_init not __init_data (patch 0002)
- Change name of lsmblob variable in ima_match_rules() (patch 0003)
- Instead of putting a struct lsmblob into the unix_skb_parms
structure put a pointer to an allocated instance. There is
currently only space for 5 u32's in unix_skb_parms and it is
likely to get even tighter. Fortunately, the lifecycle
management of the allocated lsmblob is simple. (patch 0005)
- Dropped Acks due to the above change (patch 0005)
- Improved commentary on secmark labeling scaffolding. (patch 0006)
- Reduced secmark related labeling scaffolding. (patch 0006)
- Replace use of the zeroth entry of an lsmblob in scaffolding
with a function lsmblob_value() to hopefully make it less
obscure. (patch 0006)
- Convert security_secmark_relabel_packet to use lsmblob as
this reduces much of the most contentious scaffolding. (patch 0006)
- Dropped Acks due to the above change (patch 0006)
- Added BUILD_BUG_ON() for CIPSO tag 6. (patch 0018)
- Reworked audit subject information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use subj="?". (patch 0020)
- Dropped Acks due to the above change (patch 0020)
- Reworked audit object information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use obj="?". (patch 0021)
- Dropped Acks due to the above change (patch 0021)
- Enhanced documentation (patch 0022)
- Removed unnecessary error code check in security_getprocattr()
(patch 0021)
v15: Rebase to 5.6-rc1
- Revise IMA data use (patch 0002)
Incorporate feedback from v14
- Fix lockdown module registration naming (patch 0002)
- Revise how /proc/self/attr/context is gathered. (patch 0022)
- Revise access modes on /proc/self/attr/context. (patch 0022)
- Revise documentation on LSM external interfaces. (patch 0022)
v14: Rebase to 5.5-rc5
Incorporate feedback from v13
- Use an array of audit rules (patch 0002)
- Significant change, removed Acks (patch 0002)
- Remove unneeded include (patch 0013)
- Use context.len correctly (patch 0015)
- Reorder code to be more sensible (patch 0016)
- Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
v13: Rebase to 5.5-rc2
Incorporate feedback from v12
- Print lsmblob size with %z (Patch 0002)
- Convert lockdown LSM initialization. (Patch 0002)
- Restore error check in nft_secmark_compute_secid (Patch 0006)
- Correct blob scaffolding in ima_must_appraise() (Patch 0009)
- Make security_setprocattr() clearer (Patch 0013)
- Use lsm_task_display more widely (Patch 0013)
- Use passed size in lsmcontext_init() (Patch 0014)
- Don't add a smack_release_secctx() hook (Patch 0014)
- Don't print warning in security_release_secctx() (Patch 0014)
- Don't duplicate the label in nfs4_label_init_security() (Patch 0016)
- Remove reviewed-by as code has significant change (Patch 0016)
- Send the entire lsmblob for Tag 6 (Patch 0019)
- Fix description of socket_getpeersec_stream parameters (Patch 0023)
- Retain LSMBLOB_FIRST. What was I thinking? (Patch 0023)
- Add compound context to LSM documentation (Patch 0023)
v12: Rebase to 5.5-rc1
Fixed a couple of incorrect contractions in the text.
v11: Rebase to 5.4-rc6
Incorporate feedback from v10
- Disambiguate reading /proc/.../attr/display by restricting
all use of the interface to the current process.
- Fix a merge error in AppArmor's display attribute check
v10: Ask the security modules if the display can be changed.
v9: There is no version 9
v8: Incorporate feedback from v7
- Minor clean-up in display value management
- refactor "compound" context creation to use a common
append_ctx() function.
v7: Incorporate feedback from v6
- Make setting the display a privileged operation. The
availability of compound contexts reduces the need for
setting the display.
v6: Incorporate feedback from v5
- Add subj_<lsm>= and obj_<lsm>= fields to audit records
- Add /proc/.../attr/context to get the full context in
lsmname\0value\0... format as suggested by Simon McVittie
- Add SO_PEERCONTEXT for getsockopt() to get the full context
in the same format, also suggested by Simon McVittie.
- Add /sys/kernel/security/lsm_display_default to provide
the display default value.
v5: Incorporate feedback from v4
- Initialize the lsmcontext in security_secid_to_secctx()
- Clear the lsmcontext in all security_release_secctx() cases
- Don't use the "display" on strictly internal context
interfaces.
- The SELinux binder hooks check for cases where the context
"display" isn't compatible with SELinux.
v4: Incorporate feedback from v3
- Mark new lsm_<blob>_alloc functions static
- Replace the lsm and slot fields of the security_hook_list
with a pointer to a LSM allocated lsm_id structure. The
LSM identifies if it needs a slot explicitly. Use the
lsm_id rather than make security_add_hooks return the
slot value.
- Validate slot values used in security.c
- Reworked the "display" process attribute handling so that
it works right and doesn't use goofy list processing.
- fix display value check in dentry_init_security
- Replace audit_log of secids with '?' instead of deleting
the audit log
v3: Incorporate feedback from v2
- Make lsmblob parameter and variable names more
meaningful, changing "le" and "l" to "blob".
- Improve consistency of constant naming.
- Do more sanity checking during LSM initialization.
- Be a bit clearer about what is temporary scaffolding.
- Rather than clutter security_getpeersec_dgram with
otherwise unnecessary checks remove the apparmor
stub, which does nothing useful.

Patch 01 moves management of the sock security blob
from the individual modules to the infrastructure.

Patches 02-03 introduce a structure "lsmblob" that will gradually
replace the "secid" as a shorthand for security module information.
At this point lsmblob contains an array of u32 secids, one "slot"
for each of the security modules compiled into the kernel that
used secids. A "slot" is allocated when a security module requests
one.

Patch 04 provides mechanism for the IMA subsystem to identify
explicitly which LSM is subject to IMA policy. This includes
a boot option for specifying the default and an additional option
in IMA rules "lsm=".

Patches 05-13 change LSM interfaces to use the lsmblob instead
of secids. It is important that the lsmblob be a fixed size entity
that does not have to be allocated. Several of the places
where it is used would have performance and/or locking
issues with dynamic allocation.

Patch 14 provides a mechanism for a process to identify which
security module's hooks should be used when displaying or
converting a security context string. A new interface
/proc/self/attr/interface_lsm contains the name of the security
module to show. Reading from this file will present the name of
the module, while writing to it will set the value. Only names
of active security modules are accepted. Internally, the name
is translated to the appropriate "slot" number for the module
which is then stored in the task security blob. Setting the
display requires that all modules using the /proc interfaces
allow the transition. The interface LSM of other processess
can be neither read nor written. All suggested cases for
reading the interface LSM of a different process have race
conditions.

Patch 15 Starts the process of changing how a security
context is represented. Since it is possible for a
security context to have been generated by more than one
security module it is now necessary to note which module
created a security context so that the correct "release"
hook can be called. There are several places where the
module that created a security context cannot be inferred.

This is achieved by introducing a "lsmcontext" structure
which contains the context string, its length and the
"slot" number of the security module that created it.
The security_release_secctx() interface is changed,
replacing the (string,len) pointer pair with a lsmcontext
pointer.

Patches 16-18 convert the security interfaces from
(string,len) pointer pairs to a lsmcontext pointer.
The slot number identifying the creating module is
added by the infrastructure. Where the security context
is stored for extended periods the data type is changed.

The Netlabel code is converted to save lsmblob structures
instead of secids in Patch 19. This is not strictly
necessary as there can only be one security module that
uses Netlabel at this point. Using a lsmblob is much
cleaner, as the interfaces that use the data have all
been converted.

Patch 20 adds checks to the binder hooks which verify
that both ends of a transaction use the same interface LSM.

Patches 21-23 add addition audit records for subject and
object LSM data when there are multiple security modules
with such data. The AUDIT_MAC_TASK_CONTEXTS record is used
in conjuction with a "subj=?" field to identify the subject
data. The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction
with a "obj=?" field to identify the object data. The
AUDIT_MAC_TASK_CONTEXTS record identifies the security module
with the data: subj_selinux="xyz_t" subj_apparmor="abc". The
AUDIT_MAC_OBJ_CONTEXTS record identifies the security module
with the data: obj_selinux="xyz_t obj_apparmor="abc". While
AUDIT_MAC_TASK_CONTEXTS records will always contain an entry
for each possible security modules, AUDIT_MAC_OBJ_CONTEXTS
records will only contain entries for security modules for
which the object in question has data.

An example of the MAC_TASK_CONTEXTS (1420) record is:

type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor="=unconfined"
subj_smack="_"

An example of the MAC_OBJ_CONTEXTS (1421) record is:

type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux="unconfined_u:object_r:user_home_t:s0"

Patch 24 adds a new interface for getting the compound security
contexts, /proc/self/attr/context. An example of the content
of this file is:

selinux\0one_u:one_r:one_t:s0-s0:c0.c1023\0apparmor\0unconfined\0

Finally, with all interference on the AppArmor hooks removed,
Patch 25 removes the exclusive bit from AppArmor. An unnecessary
stub hook was also removed.

The Ubuntu project is using an earlier version of this patchset in
their distribution to enable stacking for containers.

Performance measurements to date have the change within the "noise".
The sockperf and dbench results are on the order of 0.2% to 0.8%
difference, with better performance being as common as worse. The
benchmarks were run with AppArmor and Smack on Ubuntu.

https://github.com/cschaufler/lsm-stacking.git#stack-5.14-rc2-v28

Signed-off-by: Casey Schaufler <[email protected]>

Casey Schaufler (25):
LSM: Infrastructure management of the sock security
LSM: Add the lsmblob data structure.
LSM: provide lsm name and id slot mappings
IMA: avoid label collisions with stacked LSMs
LSM: Use lsmblob in security_audit_rule_match
LSM: Use lsmblob in security_kernel_act_as
LSM: Use lsmblob in security_secctx_to_secid
LSM: Use lsmblob in security_secid_to_secctx
LSM: Use lsmblob in security_ipc_getsecid
LSM: Use lsmblob in security_task_getsecid
LSM: Use lsmblob in security_inode_getsecid
LSM: Use lsmblob in security_cred_getsecid
IMA: Change internal interfaces to use lsmblobs
LSM: Specify which LSM to display
LSM: Ensure the correct LSM context releaser
LSM: Use lsmcontext in security_secid_to_secctx
LSM: Use lsmcontext in security_inode_getsecctx
LSM: security_secid_to_secctx in netlink netfilter
NET: Store LSM netlabel data in a lsmblob
LSM: Verify LSM display sanity in binder
audit: support non-syscall auxiliary records
Audit: Add record for multiple process LSM attributes
Audit: Add record for multiple object LSM attributes
LSM: Add /proc attr entry for full LSM context
AppArmor: Remove the exclusive flag

Documentation/ABI/testing/ima_policy | 8 +-
Documentation/ABI/testing/procfs-attr-context | 14 +
.../ABI/testing/procfs-attr-lsm_display | 22 +
Documentation/security/lsm.rst | 28 +
drivers/android/binder.c | 26 +-
fs/ceph/xattr.c | 6 +-
fs/nfs/nfs4proc.c | 8 +-
fs/nfsd/nfs4xdr.c | 20 +-
fs/proc/base.c | 2 +
include/linux/audit.h | 35 +-
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 36 +-
include/linux/security.h | 192 +++++-
include/net/netlabel.h | 10 +-
include/net/scm.h | 15 +-
include/net/xfrm.h | 13 +-
include/uapi/linux/audit.h | 2 +
kernel/audit.c | 186 ++++--
kernel/audit.h | 8 +-
kernel/auditfilter.c | 35 +-
kernel/auditsc.c | 145 ++---
kernel/cred.c | 12 +-
net/ipv4/cipso_ipv4.c | 26 +-
net/ipv4/ip_sockglue.c | 12 +-
net/netfilter/nf_conntrack_netlink.c | 24 +-
net/netfilter/nf_conntrack_standalone.c | 11 +-
net/netfilter/nfnetlink_queue.c | 38 +-
net/netfilter/nft_meta.c | 10 +-
net/netfilter/xt_SECMARK.c | 7 +-
net/netlabel/netlabel_kapi.c | 6 +-
net/netlabel/netlabel_unlabeled.c | 103 ++--
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 17 +-
net/netlabel/netlabel_user.h | 2 +-
net/xfrm/xfrm_policy.c | 8 +-
net/xfrm/xfrm_state.c | 18 +-
security/apparmor/include/apparmor.h | 3 +-
security/apparmor/include/net.h | 6 +-
security/apparmor/include/procattr.h | 2 +-
security/apparmor/lsm.c | 105 ++--
security/apparmor/procattr.c | 22 +-
security/bpf/hooks.c | 12 +-
security/commoncap.c | 7 +-
security/integrity/ima/ima.h | 10 +-
security/integrity/ima/ima_api.c | 12 +-
security/integrity/ima/ima_appraise.c | 9 +-
security/integrity/ima/ima_main.c | 60 +-
security/integrity/ima/ima_policy.c | 89 ++-
security/integrity/integrity_audit.c | 5 +-
security/landlock/cred.c | 2 +-
security/landlock/fs.c | 2 +-
security/landlock/ptrace.c | 2 +-
security/landlock/setup.c | 5 +
security/landlock/setup.h | 1 +
security/loadpin/loadpin.c | 8 +-
security/lockdown/lockdown.c | 7 +-
security/safesetid/lsm.c | 8 +-
security/security.c | 576 ++++++++++++++++--
security/selinux/hooks.c | 99 +--
security/selinux/include/classmap.h | 2 +-
security/selinux/include/objsec.h | 5 +
security/selinux/include/security.h | 1 +
security/selinux/netlabel.c | 25 +-
security/selinux/ss/services.c | 4 +-
security/smack/smack.h | 6 +
security/smack/smack_access.c | 2 +-
security/smack/smack_lsm.c | 91 +--
security/smack/smack_netfilter.c | 8 +-
security/smack/smackfs.c | 13 +-
security/tomoyo/tomoyo.c | 8 +-
security/yama/yama_lsm.c | 7 +-
71 files changed, 1710 insertions(+), 624 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-context
create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display

--
2.31.1


2021-07-22 00:51:00

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 01/25] LSM: Infrastructure management of the sock security

Move management of the sock->sk_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Acked-by: Paul Moore <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
---
include/linux/lsm_hooks.h | 1 +
security/apparmor/include/net.h | 6 ++-
security/apparmor/lsm.c | 38 ++++-----------
security/security.c | 36 +++++++++++++-
security/selinux/hooks.c | 78 +++++++++++++++----------------
security/selinux/include/objsec.h | 5 ++
security/selinux/netlabel.c | 23 ++++-----
security/smack/smack.h | 5 ++
security/smack/smack_lsm.c | 66 ++++++++++++--------------
security/smack/smack_netfilter.c | 8 ++--
10 files changed, 145 insertions(+), 121 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 5c4c5c0602cb..afd3b16875b0 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1588,6 +1588,7 @@ struct lsm_blob_sizes {
int lbs_cred;
int lbs_file;
int lbs_inode;
+ int lbs_sock;
int lbs_superblock;
int lbs_ipc;
int lbs_msg_msg;
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
index aadb4b29fb66..fac8999ba7a3 100644
--- a/security/apparmor/include/net.h
+++ b/security/apparmor/include/net.h
@@ -51,7 +51,11 @@ struct aa_sk_ctx {
struct aa_label *peer;
};

-#define SK_CTX(X) ((X)->sk_security)
+static inline struct aa_sk_ctx *aa_sock(const struct sock *sk)
+{
+ return sk->sk_security + apparmor_blob_sizes.lbs_sock;
+}
+
#define SOCK_ctx(X) SOCK_INODE(X)->i_security
#define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P) \
struct lsm_network_audit NAME ## _net = { .sk = (SK), \
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index f72406fe1bf2..4113516fb62e 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -775,33 +775,15 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo
return error;
}

-/**
- * apparmor_sk_alloc_security - allocate and attach the sk_security field
- */
-static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
-{
- struct aa_sk_ctx *ctx;
-
- ctx = kzalloc(sizeof(*ctx), flags);
- if (!ctx)
- return -ENOMEM;
-
- SK_CTX(sk) = ctx;
-
- return 0;
-}
-
/**
* apparmor_sk_free_security - free the sk_security field
*/
static void apparmor_sk_free_security(struct sock *sk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);

- SK_CTX(sk) = NULL;
aa_put_label(ctx->label);
aa_put_label(ctx->peer);
- kfree(ctx);
}

/**
@@ -810,8 +792,8 @@ static void apparmor_sk_free_security(struct sock *sk)
static void apparmor_sk_clone_security(const struct sock *sk,
struct sock *newsk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
- struct aa_sk_ctx *new = SK_CTX(newsk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);
+ struct aa_sk_ctx *new = aa_sock(newsk);

if (new->label)
aa_put_label(new->label);
@@ -867,7 +849,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family,
label = aa_get_current_label();

if (sock->sk) {
- struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
+ struct aa_sk_ctx *ctx = aa_sock(sock->sk);

aa_put_label(ctx->label);
ctx->label = aa_get_label(label);
@@ -1052,7 +1034,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
*/
static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);

if (!skb->secmark)
return 0;
@@ -1065,7 +1047,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)

static struct aa_label *sk_peer_label(struct sock *sk)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);

if (ctx->peer)
return ctx->peer;
@@ -1149,7 +1131,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock,
*/
static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);

if (!ctx->label)
ctx->label = aa_get_current_label();
@@ -1159,7 +1141,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
- struct aa_sk_ctx *ctx = SK_CTX(sk);
+ struct aa_sk_ctx *ctx = aa_sock(sk);

if (!skb->secmark)
return 0;
@@ -1176,6 +1158,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
.lbs_cred = sizeof(struct aa_task_ctx *),
.lbs_file = sizeof(struct aa_file_ctx),
.lbs_task = sizeof(struct aa_task_ctx),
+ .lbs_sock = sizeof(struct aa_sk_ctx),
};

static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
@@ -1212,7 +1195,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),

- LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),

@@ -1764,7 +1746,7 @@ static unsigned int apparmor_ip_postroute(void *priv,
if (sk == NULL)
return NF_ACCEPT;

- ctx = SK_CTX(sk);
+ ctx = aa_sock(sk);
if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
skb->secmark, sk))
return NF_ACCEPT;
diff --git a/security/security.c b/security/security.c
index 09533cbb7221..335c313a668d 100644
--- a/security/security.c
+++ b/security/security.c
@@ -29,6 +29,7 @@
#include <linux/string.h>
#include <linux/msg.h>
#include <net/flow.h>
+#include <net/sock.h>

#define MAX_LSM_EVM_XATTR 2

@@ -203,6 +204,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
+ lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
}
@@ -339,6 +341,7 @@ static void __init ordered_lsm_init(void)
init_debug("inode blob size = %d\n", blob_sizes.lbs_inode);
init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc);
init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg);
+ init_debug("sock blob size = %d\n", blob_sizes.lbs_sock);
init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
init_debug("task blob size = %d\n", blob_sizes.lbs_task);

@@ -658,6 +661,28 @@ static int lsm_msg_msg_alloc(struct msg_msg *mp)
return 0;
}

+/**
+ * lsm_sock_alloc - allocate a composite sock blob
+ * @sock: the sock that needs a blob
+ * @priority: allocation mode
+ *
+ * Allocate the sock blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+static int lsm_sock_alloc(struct sock *sock, gfp_t priority)
+{
+ if (blob_sizes.lbs_sock == 0) {
+ sock->sk_security = NULL;
+ return 0;
+ }
+
+ sock->sk_security = kzalloc(blob_sizes.lbs_sock, priority);
+ if (sock->sk_security == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
/**
* lsm_early_task - during initialization allocate a composite task blob
* @task: the task that needs a blob
@@ -2258,12 +2283,21 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram);

int security_sk_alloc(struct sock *sk, int family, gfp_t priority)
{
- return call_int_hook(sk_alloc_security, 0, sk, family, priority);
+ int rc = lsm_sock_alloc(sk, priority);
+
+ if (unlikely(rc))
+ return rc;
+ rc = call_int_hook(sk_alloc_security, 0, sk, family, priority);
+ if (unlikely(rc))
+ security_sk_free(sk);
+ return rc;
}

void security_sk_free(struct sock *sk)
{
call_void_hook(sk_free_security, sk);
+ kfree(sk->sk_security);
+ sk->sk_security = NULL;
}

void security_sk_clone(const struct sock *sk, struct sock *newsk)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index b0032c42333e..e2c4a1fd952f 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4642,7 +4642,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec,

static int sock_has_perm(struct sock *sk, u32 perms)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct common_audit_data ad;
struct lsm_network_audit net = {0,};

@@ -4699,7 +4699,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
isec->initialized = LABEL_INITIALIZED;

if (sock->sk) {
- sksec = sock->sk->sk_security;
+ sksec = selinux_sock(sock->sk);
sksec->sclass = sclass;
sksec->sid = sid;
/* Allows detection of the first association on this socket */
@@ -4715,8 +4715,8 @@ static int selinux_socket_post_create(struct socket *sock, int family,
static int selinux_socket_socketpair(struct socket *socka,
struct socket *sockb)
{
- struct sk_security_struct *sksec_a = socka->sk->sk_security;
- struct sk_security_struct *sksec_b = sockb->sk->sk_security;
+ struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
+ struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);

sksec_a->peer_sid = sksec_b->sid;
sksec_b->peer_sid = sksec_a->sid;
@@ -4731,7 +4731,7 @@ static int selinux_socket_socketpair(struct socket *socka,
static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
{
struct sock *sk = sock->sk;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
u16 family;
int err;

@@ -4866,7 +4866,7 @@ static int selinux_socket_connect_helper(struct socket *sock,
struct sockaddr *address, int addrlen)
{
struct sock *sk = sock->sk;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
int err;

err = sock_has_perm(sk, SOCKET__CONNECT);
@@ -5045,9 +5045,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
struct sock *other,
struct sock *newsk)
{
- struct sk_security_struct *sksec_sock = sock->sk_security;
- struct sk_security_struct *sksec_other = other->sk_security;
- struct sk_security_struct *sksec_new = newsk->sk_security;
+ struct sk_security_struct *sksec_sock = selinux_sock(sock);
+ struct sk_security_struct *sksec_other = selinux_sock(other);
+ struct sk_security_struct *sksec_new = selinux_sock(newsk);
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
int err;
@@ -5079,8 +5079,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
static int selinux_socket_unix_may_send(struct socket *sock,
struct socket *other)
{
- struct sk_security_struct *ssec = sock->sk->sk_security;
- struct sk_security_struct *osec = other->sk->sk_security;
+ struct sk_security_struct *ssec = selinux_sock(sock->sk);
+ struct sk_security_struct *osec = selinux_sock(other->sk);
struct common_audit_data ad;
struct lsm_network_audit net = {0,};

@@ -5122,7 +5122,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
u16 family)
{
int err = 0;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
u32 sk_sid = sksec->sid;
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
@@ -5155,7 +5155,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int err;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
u16 family = sk->sk_family;
u32 sk_sid = sksec->sid;
struct common_audit_data ad;
@@ -5223,13 +5223,15 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
return err;
}

-static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
- int __user *optlen, unsigned len)
+static int selinux_socket_getpeersec_stream(struct socket *sock,
+ char __user *optval,
+ int __user *optlen,
+ unsigned int len)
{
int err = 0;
char *scontext;
u32 scontext_len;
- struct sk_security_struct *sksec = sock->sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sock->sk);
u32 peer_sid = SECSID_NULL;

if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
@@ -5289,34 +5291,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *

static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
{
- struct sk_security_struct *sksec;
-
- sksec = kzalloc(sizeof(*sksec), priority);
- if (!sksec)
- return -ENOMEM;
+ struct sk_security_struct *sksec = selinux_sock(sk);

sksec->peer_sid = SECINITSID_UNLABELED;
sksec->sid = SECINITSID_UNLABELED;
sksec->sclass = SECCLASS_SOCKET;
selinux_netlbl_sk_security_reset(sksec);
- sk->sk_security = sksec;

return 0;
}

static void selinux_sk_free_security(struct sock *sk)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

- sk->sk_security = NULL;
selinux_netlbl_sk_security_free(sksec);
- kfree(sksec);
}

static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
{
- struct sk_security_struct *sksec = sk->sk_security;
- struct sk_security_struct *newsksec = newsk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
+ struct sk_security_struct *newsksec = selinux_sock(newsk);

newsksec->sid = sksec->sid;
newsksec->peer_sid = sksec->peer_sid;
@@ -5330,7 +5325,7 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
if (!sk)
*secid = SECINITSID_ANY_SOCKET;
else {
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

*secid = sksec->sid;
}
@@ -5340,7 +5335,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
{
struct inode_security_struct *isec =
inode_security_novalidate(SOCK_INODE(parent));
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
sk->sk_family == PF_UNIX)
@@ -5355,7 +5350,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
static int selinux_sctp_assoc_request(struct sctp_endpoint *ep,
struct sk_buff *skb)
{
- struct sk_security_struct *sksec = ep->base.sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
u8 peerlbl_active;
@@ -5506,8 +5501,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
struct sock *newsk)
{
- struct sk_security_struct *sksec = sk->sk_security;
- struct sk_security_struct *newsksec = newsk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
+ struct sk_security_struct *newsksec = selinux_sock(newsk);

/* If policy does not support SECCLASS_SCTP_SOCKET then call
* the non-sctp clone version.
@@ -5524,7 +5519,7 @@ static void selinux_sctp_sk_clone(struct sctp_endpoint *ep, struct sock *sk,
static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
int err;
u16 family = req->rsk_ops->family;
u32 connsid;
@@ -5545,7 +5540,7 @@ static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
static void selinux_inet_csk_clone(struct sock *newsk,
const struct request_sock *req)
{
- struct sk_security_struct *newsksec = newsk->sk_security;
+ struct sk_security_struct *newsksec = selinux_sock(newsk);

newsksec->sid = req->secid;
newsksec->peer_sid = req->peer_secid;
@@ -5562,7 +5557,7 @@ static void selinux_inet_csk_clone(struct sock *newsk,
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
{
u16 family = sk->sk_family;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

/* handle mapped IPv4 packets arriving via IPv6 sockets */
if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
@@ -5646,7 +5641,7 @@ static int selinux_tun_dev_attach_queue(void *security)
static int selinux_tun_dev_attach(struct sock *sk, void *security)
{
struct tun_security_struct *tunsec = security;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

/* we don't currently perform any NetLabel based labeling here and it
* isn't clear that we would want to do so anyway; while we could apply
@@ -5790,7 +5785,7 @@ static unsigned int selinux_ip_output(struct sk_buff *skb,
return NF_ACCEPT;

/* standard practice, label using the parent socket */
- sksec = sk->sk_security;
+ sksec = selinux_sock(sk);
sid = sksec->sid;
} else
sid = SECINITSID_KERNEL;
@@ -5829,7 +5824,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,

if (sk == NULL)
return NF_ACCEPT;
- sksec = sk->sk_security;
+ sksec = selinux_sock(sk);

ad.type = LSM_AUDIT_DATA_NET;
ad.u.net = &net;
@@ -5921,7 +5916,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
u32 skb_sid;
struct sk_security_struct *sksec;

- sksec = sk->sk_security;
+ sksec = selinux_sock(sk);
if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
return NF_DROP;
/* At this point, if the returned skb peerlbl is SECSID_NULL
@@ -5950,7 +5945,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
} else {
/* Locally generated packet, fetch the security label from the
* associated socket. */
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
peer_sid = sksec->sid;
secmark_perm = PACKET__SEND;
}
@@ -6015,7 +6010,7 @@ static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
unsigned int data_len = skb->len;
unsigned char *data = skb->data;
struct nlmsghdr *nlh;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
u16 sclass = sksec->sclass;
u32 perm;

@@ -7041,6 +7036,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
.lbs_inode = sizeof(struct inode_security_struct),
.lbs_ipc = sizeof(struct ipc_security_struct),
.lbs_msg_msg = sizeof(struct msg_security_struct),
+ .lbs_sock = sizeof(struct sk_security_struct),
.lbs_superblock = sizeof(struct superblock_security_struct),
};

diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 2953132408bf..007d1ae7ee27 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -194,4 +194,9 @@ static inline struct superblock_security_struct *selinux_superblock(
return superblock->s_security + selinux_blob_sizes.lbs_superblock;
}

+static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
+{
+ return sock->sk_security + selinux_blob_sizes.lbs_sock;
+}
+
#endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index abaab7683840..6a94b31b5472 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -17,6 +17,7 @@
#include <linux/gfp.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
+#include <linux/lsm_hooks.h>
#include <net/sock.h>
#include <net/netlabel.h>
#include <net/ip.h>
@@ -67,7 +68,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
{
int rc;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct netlbl_lsm_secattr *secattr;

if (sksec->nlbl_secattr != NULL)
@@ -100,7 +101,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
const struct sock *sk,
u32 sid)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;

if (secattr == NULL)
@@ -235,7 +236,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
* being labeled by it's parent socket, if it is just exit */
sk = skb_to_full_sk(skb);
if (sk != NULL) {
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

if (sksec->nlbl_state != NLBL_REQSKB)
return 0;
@@ -273,7 +274,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_endpoint *ep,
{
int rc;
struct netlbl_lsm_secattr secattr;
- struct sk_security_struct *sksec = ep->base.sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(ep->base.sk);
struct sockaddr_in addr4;
struct sockaddr_in6 addr6;

@@ -352,7 +353,7 @@ int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
*/
void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

if (family == PF_INET)
sksec->nlbl_state = NLBL_LABELED;
@@ -370,8 +371,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
*/
void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
{
- struct sk_security_struct *sksec = sk->sk_security;
- struct sk_security_struct *newsksec = newsk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
+ struct sk_security_struct *newsksec = selinux_sock(newsk);

newsksec->nlbl_state = sksec->nlbl_state;
}
@@ -389,7 +390,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
{
int rc;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct netlbl_lsm_secattr *secattr;

if (family != PF_INET && family != PF_INET6)
@@ -504,7 +505,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
{
int rc = 0;
struct sock *sk = sock->sk;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct netlbl_lsm_secattr secattr;

if (selinux_netlbl_option(level, optname) &&
@@ -542,7 +543,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
struct sockaddr *addr)
{
int rc;
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);
struct netlbl_lsm_secattr *secattr;

/* connected sockets are allowed to disconnect when the address family
@@ -581,7 +582,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
int selinux_netlbl_socket_connect_locked(struct sock *sk,
struct sockaddr *addr)
{
- struct sk_security_struct *sksec = sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(sk);

if (sksec->nlbl_state != NLBL_REQSKB &&
sksec->nlbl_state != NLBL_CONNLABELED)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index c3cfbdf4944a..b5bdf947792f 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -363,6 +363,11 @@ static inline struct superblock_smack *smack_superblock(
return superblock->s_security + smack_blob_sizes.lbs_superblock;
}

+static inline struct socket_smack *smack_sock(const struct sock *sock)
+{
+ return sock->sk_security + smack_blob_sizes.lbs_sock;
+}
+
/*
* Is the directory transmuting?
*/
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 223a6da0e6dc..1ee0bf1493f6 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1429,7 +1429,7 @@ static int smack_inode_getsecurity(struct user_namespace *mnt_userns,
if (sock == NULL || sock->sk == NULL)
return -EOPNOTSUPP;

- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);

if (strcmp(name, XATTR_SMACK_IPIN) == 0)
isp = ssp->smk_in;
@@ -1811,7 +1811,7 @@ static int smack_file_receive(struct file *file)

if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
sock = SOCKET_I(inode);
- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);
tsp = smack_cred(current_cred());
/*
* If the receiving process can't write to the
@@ -2232,11 +2232,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
{
struct smack_known *skp = smk_of_current();
- struct socket_smack *ssp;
-
- ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
- if (ssp == NULL)
- return -ENOMEM;
+ struct socket_smack *ssp = smack_sock(sk);

/*
* Sockets created by kernel threads receive web label.
@@ -2250,11 +2246,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
}
ssp->smk_packet = NULL;

- sk->sk_security = ssp;
-
return 0;
}

+#ifdef SMACK_IPV6_PORT_LABELING
/**
* smack_sk_free_security - Free a socket blob
* @sk: the socket
@@ -2263,7 +2258,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
*/
static void smack_sk_free_security(struct sock *sk)
{
-#ifdef SMACK_IPV6_PORT_LABELING
struct smk_port_label *spp;

if (sk->sk_family == PF_INET6) {
@@ -2276,9 +2270,8 @@ static void smack_sk_free_security(struct sock *sk)
}
rcu_read_unlock();
}
-#endif
- kfree(sk->sk_security);
}
+#endif

/**
* smack_ipv4host_label - check host based restrictions
@@ -2391,7 +2384,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
*/
static int smack_netlbl_add(struct sock *sk)
{
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct smack_known *skp = ssp->smk_out;
int rc;

@@ -2423,7 +2416,7 @@ static int smack_netlbl_add(struct sock *sk)
*/
static void smack_netlbl_delete(struct sock *sk)
{
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);

/*
* Take the label off the socket if one is set.
@@ -2455,7 +2448,7 @@ static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
struct smack_known *skp;
int rc = 0;
struct smack_known *hkp;
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct smk_audit_info ad;

rcu_read_lock();
@@ -2528,7 +2521,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
{
struct sock *sk = sock->sk;
struct sockaddr_in6 *addr6;
- struct socket_smack *ssp = sock->sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sock->sk);
struct smk_port_label *spp;
unsigned short port = 0;

@@ -2617,7 +2610,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
int act)
{
struct smk_port_label *spp;
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct smack_known *skp = NULL;
unsigned short port;
struct smack_known *object;
@@ -2710,7 +2703,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
if (sock == NULL || sock->sk == NULL)
return -EOPNOTSUPP;

- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);

if (strcmp(name, XATTR_SMACK_IPIN) == 0)
ssp->smk_in = skp;
@@ -2758,7 +2751,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
* Sockets created by kernel threads receive web label.
*/
if (unlikely(current->flags & PF_KTHREAD)) {
- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);
ssp->smk_in = &smack_known_web;
ssp->smk_out = &smack_known_web;
}
@@ -2783,8 +2776,8 @@ static int smack_socket_post_create(struct socket *sock, int family,
static int smack_socket_socketpair(struct socket *socka,
struct socket *sockb)
{
- struct socket_smack *asp = socka->sk->sk_security;
- struct socket_smack *bsp = sockb->sk->sk_security;
+ struct socket_smack *asp = smack_sock(socka->sk);
+ struct socket_smack *bsp = smack_sock(sockb->sk);

asp->smk_packet = bsp->smk_out;
bsp->smk_packet = asp->smk_out;
@@ -2847,7 +2840,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
rsp = smack_ipv6host_label(sip);
if (rsp != NULL) {
- struct socket_smack *ssp = sock->sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sock->sk);

rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
SMK_CONNECTING);
@@ -3575,9 +3568,9 @@ static int smack_unix_stream_connect(struct sock *sock,
{
struct smack_known *skp;
struct smack_known *okp;
- struct socket_smack *ssp = sock->sk_security;
- struct socket_smack *osp = other->sk_security;
- struct socket_smack *nsp = newsk->sk_security;
+ struct socket_smack *ssp = smack_sock(sock);
+ struct socket_smack *osp = smack_sock(other);
+ struct socket_smack *nsp = smack_sock(newsk);
struct smk_audit_info ad;
int rc = 0;
#ifdef CONFIG_AUDIT
@@ -3623,8 +3616,8 @@ static int smack_unix_stream_connect(struct sock *sock,
*/
static int smack_unix_may_send(struct socket *sock, struct socket *other)
{
- struct socket_smack *ssp = sock->sk->sk_security;
- struct socket_smack *osp = other->sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sock->sk);
+ struct socket_smack *osp = smack_sock(other->sk);
struct smk_audit_info ad;
int rc;

@@ -3661,7 +3654,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
- struct socket_smack *ssp = sock->sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sock->sk);
struct smack_known *rsp;
#endif
int rc = 0;
@@ -3873,7 +3866,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
netlbl_secattr_init(&secattr);

if (sk)
- ssp = sk->sk_security;
+ ssp = smack_sock(sk);

if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
skp = smack_from_secattr(&secattr, ssp);
@@ -3895,7 +3888,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
*/
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct smack_known *skp = NULL;
int rc = 0;
struct smk_audit_info ad;
@@ -3999,7 +3992,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
int slen = 1;
int rc = 0;

- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);
if (ssp->smk_packet != NULL) {
rcp = ssp->smk_packet->smk_known;
slen = strlen(rcp) + 1;
@@ -4048,7 +4041,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,

switch (family) {
case PF_UNIX:
- ssp = sock->sk->sk_security;
+ ssp = smack_sock(sock->sk);
s = ssp->smk_out->smk_secid;
break;
case PF_INET:
@@ -4097,7 +4090,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent)
(sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
return;

- ssp = sk->sk_security;
+ ssp = smack_sock(sk);
ssp->smk_in = skp;
ssp->smk_out = skp;
/* cssp->smk_packet is already set in smack_inet_csk_clone() */
@@ -4117,7 +4110,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
{
u16 family = sk->sk_family;
struct smack_known *skp;
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct sockaddr_in addr;
struct iphdr *hdr;
struct smack_known *hskp;
@@ -4203,7 +4196,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
static void smack_inet_csk_clone(struct sock *sk,
const struct request_sock *req)
{
- struct socket_smack *ssp = sk->sk_security;
+ struct socket_smack *ssp = smack_sock(sk);
struct smack_known *skp;

if (req->peer_secid != 0) {
@@ -4697,6 +4690,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_inode = sizeof(struct inode_smack),
.lbs_ipc = sizeof(struct smack_known *),
.lbs_msg_msg = sizeof(struct smack_known *),
+ .lbs_sock = sizeof(struct socket_smack),
.lbs_superblock = sizeof(struct superblock_smack),
};

@@ -4807,7 +4801,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
+#ifdef SMACK_IPV6_PORT_LABELING
LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
+#endif
LSM_HOOK_INIT(sock_graft, smack_sock_graft),
LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c
index fc7399b45373..635e2339579e 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -28,8 +28,8 @@ static unsigned int smack_ipv6_output(void *priv,
struct socket_smack *ssp;
struct smack_known *skp;

- if (sk && sk->sk_security) {
- ssp = sk->sk_security;
+ if (sk && smack_sock(sk)) {
+ ssp = smack_sock(sk);
skp = ssp->smk_out;
skb->secmark = skp->smk_secid;
}
@@ -46,8 +46,8 @@ static unsigned int smack_ipv4_output(void *priv,
struct socket_smack *ssp;
struct smack_known *skp;

- if (sk && sk->sk_security) {
- ssp = sk->sk_security;
+ if (sk && smack_sock(sk)) {
+ ssp = smack_sock(sk);
skp = ssp->smk_out;
skb->secmark = skp->smk_secid;
}
--
2.31.1

2021-07-22 00:52:28

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 02/25] LSM: Add the lsmblob data structure.

When more than one security module is exporting data to
audit and networking sub-systems a single 32 bit integer
is no longer sufficient to represent the data. Add a
structure to be used instead.

The lsmblob structure is currently an array of
u32 "secids". There is an entry for each of the
security modules built into the system that would
use secids if active. The system assigns the module
a "slot" when it registers hooks. If modules are
compiled in but not registered there will be unused
slots.

A new lsm_id structure, which contains the name
of the LSM and its slot number, is created. There
is an instance for each LSM, which assigns the name
and passes it to the infrastructure to set the slot.

The audit rules data is expanded to use an array of
security module data rather than a single instance.
Because IMA uses the audit rule functions it is
affected as well.

Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Acked-by: John Johansen <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
To: Mimi Zohar <[email protected]>
To: Mickaël Salaün <[email protected]>
---
include/linux/audit.h | 4 +-
include/linux/lsm_hooks.h | 12 ++++-
include/linux/security.h | 67 ++++++++++++++++++++++++--
kernel/auditfilter.c | 24 +++++-----
kernel/auditsc.c | 13 +++--
security/apparmor/lsm.c | 7 ++-
security/bpf/hooks.c | 12 ++++-
security/commoncap.c | 7 ++-
security/integrity/ima/ima_policy.c | 40 +++++++++++-----
security/landlock/cred.c | 2 +-
security/landlock/fs.c | 2 +-
security/landlock/ptrace.c | 2 +-
security/landlock/setup.c | 5 ++
security/landlock/setup.h | 1 +
security/loadpin/loadpin.c | 8 +++-
security/lockdown/lockdown.c | 7 ++-
security/safesetid/lsm.c | 8 +++-
security/security.c | 74 ++++++++++++++++++++++++-----
security/selinux/hooks.c | 8 +++-
security/smack/smack_lsm.c | 7 ++-
security/tomoyo/tomoyo.c | 8 +++-
security/yama/yama_lsm.c | 7 ++-
22 files changed, 265 insertions(+), 60 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 82b7c1116a85..418a485af114 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -11,6 +11,7 @@

#include <linux/sched.h>
#include <linux/ptrace.h>
+#include <linux/security.h>
#include <uapi/linux/audit.h>
#include <uapi/linux/netfilter/nf_tables.h>

@@ -65,8 +66,9 @@ struct audit_field {
kuid_t uid;
kgid_t gid;
struct {
+ bool lsm_isset;
char *lsm_str;
- void *lsm_rule;
+ void *lsm_rules[LSMBLOB_ENTRIES];
};
};
u32 op;
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index afd3b16875b0..c61a16f0a5bc 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1570,6 +1570,14 @@ struct security_hook_heads {
#undef LSM_HOOK
} __randomize_layout;

+/*
+ * Information that identifies a security module.
+ */
+struct lsm_id {
+ const char *lsm; /* Name of the LSM */
+ int slot; /* Slot in lsmblob if one is allocated */
+};
+
/*
* Security module hook list structure.
* For use with generic list macros for common operations.
@@ -1578,7 +1586,7 @@ struct security_hook_list {
struct hlist_node list;
struct hlist_head *head;
union security_list_options hook;
- char *lsm;
+ struct lsm_id *lsmid;
} __randomize_layout;

/*
@@ -1614,7 +1622,7 @@ extern struct security_hook_heads security_hook_heads;
extern char *lsm_names;

extern void security_add_hooks(struct security_hook_list *hooks, int count,
- char *lsm);
+ struct lsm_id *lsmid);

#define LSM_FLAG_LEGACY_MAJOR BIT(0)
#define LSM_FLAG_EXCLUSIVE BIT(1)
diff --git a/include/linux/security.h b/include/linux/security.h
index 24eda04221e9..7655bfce4b96 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -133,6 +133,65 @@ enum lockdown_reason {

extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];

+/*
+ * Data exported by the security modules
+ *
+ * Any LSM that provides secid or secctx based hooks must be included.
+ */
+#define LSMBLOB_ENTRIES ( \
+ (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \
+ (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0))
+
+struct lsmblob {
+ u32 secid[LSMBLOB_ENTRIES];
+};
+
+#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
+#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
+#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
+
+/**
+ * lsmblob_init - initialize an lsmblob structure
+ * @blob: Pointer to the data to initialize
+ * @secid: The initial secid value
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
+{
+ int i;
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++)
+ blob->secid[i] = secid;
+}
+
+/**
+ * lsmblob_is_set - report if there is an value in the lsmblob
+ * @blob: Pointer to the exported LSM data
+ *
+ * Returns true if there is a secid set, false otherwise
+ */
+static inline bool lsmblob_is_set(struct lsmblob *blob)
+{
+ struct lsmblob empty = {};
+
+ return !!memcmp(blob, &empty, sizeof(*blob));
+}
+
+/**
+ * lsmblob_equal - report if the two lsmblob's are equal
+ * @bloba: Pointer to one LSM data
+ * @blobb: Pointer to the other LSM data
+ *
+ * Returns true if all entries in the two are equal, false otherwise
+ */
+static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
+{
+ return !memcmp(bloba, blobb, sizeof(*bloba));
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
@@ -1881,8 +1940,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
#ifdef CONFIG_SECURITY
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
-void security_audit_rule_free(void *lsmrule);
+int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule);
+void security_audit_rule_free(void **lsmrule);

#else

@@ -1898,12 +1957,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
}

static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+ void **lsmrule)
{
return 0;
}

-static inline void security_audit_rule_free(void *lsmrule)
+static inline void security_audit_rule_free(void **lsmrule)
{ }

#endif /* CONFIG_SECURITY */
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index db2c6b59dfc3..a2340e81cfa7 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -74,7 +74,7 @@ static void audit_free_lsm_field(struct audit_field *f)
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
kfree(f->lsm_str);
- security_audit_rule_free(f->lsm_rule);
+ security_audit_rule_free(f->lsm_rules);
}
}

@@ -519,9 +519,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
goto exit_free;
}
entry->rule.buflen += f_val;
+ f->lsm_isset = true;
f->lsm_str = str;
err = security_audit_rule_init(f->type, f->op, str,
- (void **)&f->lsm_rule);
+ f->lsm_rules);
/* Keep currently invalid fields around in case they
* become valid after a policy reload. */
if (err == -EINVAL) {
@@ -774,7 +775,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
return 0;
}

-/* Duplicate LSM field information. The lsm_rule is opaque, so must be
+/* Duplicate LSM field information. The lsm_rules is opaque, so must be
* re-initialized. */
static inline int audit_dupe_lsm_field(struct audit_field *df,
struct audit_field *sf)
@@ -788,9 +789,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
return -ENOMEM;
df->lsm_str = lsm_str;

- /* our own (refreshed) copy of lsm_rule */
+ /* our own (refreshed) copy of lsm_rules */
ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
- (void **)&df->lsm_rule);
+ df->lsm_rules);
/* Keep currently invalid fields around in case they
* become valid after a policy reload. */
if (ret == -EINVAL) {
@@ -842,7 +843,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old)
new->tree = old->tree;
memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);

- /* deep copy this information, updating the lsm_rule fields, because
+ /* deep copy this information, updating the lsm_rules fields, because
* the originals will all be freed when the old rule is freed. */
for (i = 0; i < fcount; i++) {
switch (new->fields[i].type) {
@@ -1358,11 +1359,12 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_TYPE:
case AUDIT_SUBJ_SEN:
case AUDIT_SUBJ_CLR:
- if (f->lsm_rule) {
+ if (f->lsm_isset) {
security_task_getsecid_subj(current,
&sid);
result = security_audit_rule_match(sid,
- f->type, f->op, f->lsm_rule);
+ f->type, f->op,
+ f->lsm_rules);
}
break;
case AUDIT_EXE:
@@ -1389,7 +1391,7 @@ int audit_filter(int msgtype, unsigned int listtype)
return ret;
}

-static int update_lsm_rule(struct audit_krule *r)
+static int update_lsm_rules(struct audit_krule *r)
{
struct audit_entry *entry = container_of(r, struct audit_entry, rule);
struct audit_entry *nentry;
@@ -1421,7 +1423,7 @@ static int update_lsm_rule(struct audit_krule *r)
return err;
}

-/* This function will re-initialize the lsm_rule field of all applicable rules.
+/* This function will re-initialize the lsm_rules field of all applicable rules.
* It will traverse the filter lists serarching for rules that contain LSM
* specific filter fields. When such a rule is found, it is copied, the
* LSM field is re-initialized, and the old rule is replaced with the
@@ -1436,7 +1438,7 @@ int audit_update_lsm_rules(void)

for (i = 0; i < AUDIT_NR_FILTERS; i++) {
list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
- int res = update_lsm_rule(r);
+ int res = update_lsm_rules(r);
if (!err)
err = res;
}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 8dd73a64f921..acbd896f54a5 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -671,14 +671,13 @@ static int audit_filter_rules(struct task_struct *tsk,
match for now to avoid losing information that
may be wanted. An error message will also be
logged upon error */
- if (f->lsm_rule) {
+ if (f->lsm_isset) {
if (need_sid) {
security_task_getsecid_subj(tsk, &sid);
need_sid = 0;
}
result = security_audit_rule_match(sid, f->type,
- f->op,
- f->lsm_rule);
+ f->op, f->lsm_rules);
}
break;
case AUDIT_OBJ_USER:
@@ -688,21 +687,21 @@ static int audit_filter_rules(struct task_struct *tsk,
case AUDIT_OBJ_LEV_HIGH:
/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
also applies here */
- if (f->lsm_rule) {
+ if (f->lsm_isset) {
/* Find files that match */
if (name) {
result = security_audit_rule_match(
name->osid,
f->type,
f->op,
- f->lsm_rule);
+ f->lsm_rules);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
if (security_audit_rule_match(
n->osid,
f->type,
f->op,
- f->lsm_rule)) {
+ f->lsm_rules)) {
++result;
break;
}
@@ -713,7 +712,7 @@ static int audit_filter_rules(struct task_struct *tsk,
break;
if (security_audit_rule_match(ctx->ipc.osid,
f->type, f->op,
- f->lsm_rule))
+ f->lsm_rules))
++result;
}
break;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4113516fb62e..392e25940d1f 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1161,6 +1161,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
.lbs_sock = sizeof(struct aa_sk_ctx),
};

+static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
+ .lsm = "apparmor",
+ .slot = LSMBLOB_NEEDED
+};
+
static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
@@ -1862,7 +1867,7 @@ static int __init apparmor_init(void)
goto buffers_out;
}
security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
- "apparmor");
+ &apparmor_lsmid);

/* Report that AppArmor successfully initialized */
apparmor_initialized = 1;
diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c
index e5971fa74fd7..7a58fe9ab8c4 100644
--- a/security/bpf/hooks.c
+++ b/security/bpf/hooks.c
@@ -15,9 +15,19 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(task_free, bpf_task_storage_free),
};

+/*
+ * slot has to be LSMBLOB_NEEDED because some of the hooks
+ * supplied by this module require a slot.
+ */
+struct lsm_id bpf_lsmid __lsm_ro_after_init = {
+ .lsm = "bpf",
+ .slot = LSMBLOB_NEEDED
+};
+
static int __init bpf_lsm_init(void)
{
- security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), "bpf");
+ security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks),
+ &bpf_lsmid);
pr_info("LSM support for eBPF active\n");
return 0;
}
diff --git a/security/commoncap.c b/security/commoncap.c
index 3f810d37b71b..628685cf20e3 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1443,6 +1443,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,

#ifdef CONFIG_SECURITY

+static struct lsm_id capability_lsmid __lsm_ro_after_init = {
+ .lsm = "capability",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(capable, cap_capable),
LSM_HOOK_INIT(settime, cap_settime),
@@ -1467,7 +1472,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
static int __init capability_init(void)
{
security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
- "capability");
+ &capability_lsmid);
return 0;
}

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index fd5d46e511f1..5c40677e881c 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -80,7 +80,7 @@ struct ima_rule_entry {
bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
int pcr;
struct {
- void *rule; /* LSM file metadata specific */
+ void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */
char *args_p; /* audit value */
int type; /* audit type */
} lsm[MAX_LSM_RULES];
@@ -90,6 +90,22 @@ struct ima_rule_entry {
struct ima_template_desc *template;
};

+/**
+ * ima_lsm_isset - Is a rule set for any of the active security modules
+ * @rules: The set of IMA rules to check
+ *
+ * If a rule is set for any LSM return true, otherwise return false.
+ */
+static inline bool ima_lsm_isset(void *rules[])
+{
+ int i;
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++)
+ if (rules[i])
+ return true;
+ return false;
+}
+
/*
* Without LSM specific knowledge, the default policy can only be
* written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
@@ -335,9 +351,11 @@ static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list)
static void ima_lsm_free_rule(struct ima_rule_entry *entry)
{
int i;
+ int r;

for (i = 0; i < MAX_LSM_RULES; i++) {
- ima_filter_rule_free(entry->lsm[i].rule);
+ for (r = 0; r < LSMBLOB_ENTRIES; r++)
+ ima_filter_rule_free(entry->lsm[i].rules[r]);
kfree(entry->lsm[i].args_p);
}
}
@@ -388,8 +406,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)

ima_filter_rule_init(nentry->lsm[i].type, Audit_equal,
nentry->lsm[i].args_p,
- &nentry->lsm[i].rule);
- if (!nentry->lsm[i].rule)
+ &nentry->lsm[i].rules[0]);
+ if (!ima_lsm_isset(nentry->lsm[i].rules))
pr_warn("rule for LSM \'%s\' is undefined\n",
nentry->lsm[i].args_p);
}
@@ -578,7 +596,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
int rc = 0;
u32 osid;

- if (!rule->lsm[i].rule) {
+ if (!ima_lsm_isset(rule->lsm[i].rules)) {
if (!rule->lsm[i].args_p)
continue;
else
@@ -591,14 +609,14 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
security_inode_getsecid(inode, &osid);
rc = ima_filter_rule_match(osid, rule->lsm[i].type,
Audit_equal,
- rule->lsm[i].rule);
+ rule->lsm[i].rules);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
rc = ima_filter_rule_match(secid, rule->lsm[i].type,
Audit_equal,
- rule->lsm[i].rule);
+ rule->lsm[i].rules);
break;
default:
break;
@@ -994,7 +1012,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
{
int result;

- if (entry->lsm[lsm_rule].rule)
+ if (ima_lsm_isset(entry->lsm[lsm_rule].rules))
return -EINVAL;

entry->lsm[lsm_rule].args_p = match_strdup(args);
@@ -1004,8 +1022,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
entry->lsm[lsm_rule].type = audit_type;
result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal,
entry->lsm[lsm_rule].args_p,
- &entry->lsm[lsm_rule].rule);
- if (!entry->lsm[lsm_rule].rule) {
+ &entry->lsm[lsm_rule].rules[0]);
+ if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) {
pr_warn("rule for LSM \'%s\' is undefined\n",
entry->lsm[lsm_rule].args_p);

@@ -1812,7 +1830,7 @@ int ima_policy_show(struct seq_file *m, void *v)
}

for (i = 0; i < MAX_LSM_RULES; i++) {
- if (entry->lsm[i].rule) {
+ if (ima_lsm_isset(entry->lsm[i].rules)) {
switch (i) {
case LSM_OBJ_USER:
seq_printf(m, pt(Opt_obj_user),
diff --git a/security/landlock/cred.c b/security/landlock/cred.c
index 6725af24c684..56b121d65436 100644
--- a/security/landlock/cred.c
+++ b/security/landlock/cred.c
@@ -42,5 +42,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
__init void landlock_add_cred_hooks(void)
{
security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
- LANDLOCK_NAME);
+ &landlock_lsmid);
}
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 97b8e421f617..319e90e9290c 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -688,5 +688,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
__init void landlock_add_fs_hooks(void)
{
security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
- LANDLOCK_NAME);
+ &landlock_lsmid);
}
diff --git a/security/landlock/ptrace.c b/security/landlock/ptrace.c
index f55b82446de2..54ccf55a077a 100644
--- a/security/landlock/ptrace.c
+++ b/security/landlock/ptrace.c
@@ -116,5 +116,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
__init void landlock_add_ptrace_hooks(void)
{
security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
- LANDLOCK_NAME);
+ &landlock_lsmid);
}
diff --git a/security/landlock/setup.c b/security/landlock/setup.c
index f8e8e980454c..759e00b9436c 100644
--- a/security/landlock/setup.c
+++ b/security/landlock/setup.c
@@ -23,6 +23,11 @@ struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = {
.lbs_superblock = sizeof(struct landlock_superblock_security),
};

+struct lsm_id landlock_lsmid __lsm_ro_after_init = {
+ .lsm = LANDLOCK_NAME,
+ .slot = LSMBLOB_NOT_NEEDED,
+};
+
static int __init landlock_init(void)
{
landlock_add_cred_hooks();
diff --git a/security/landlock/setup.h b/security/landlock/setup.h
index 1daffab1ab4b..38bce5b172dc 100644
--- a/security/landlock/setup.h
+++ b/security/landlock/setup.h
@@ -14,5 +14,6 @@
extern bool landlock_initialized;

extern struct lsm_blob_sizes landlock_blob_sizes;
+extern struct lsm_id landlock_lsmid;

#endif /* _SECURITY_LANDLOCK_SETUP_H */
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index b12f7d986b1e..b569f3bc170b 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -192,6 +192,11 @@ static int loadpin_load_data(enum kernel_load_data_id id, bool contents)
return loadpin_read_file(NULL, (enum kernel_read_file_id) id, contents);
}

+static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
+ .lsm = "loadpin",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
@@ -239,7 +244,8 @@ static int __init loadpin_init(void)
pr_info("ready to pin (currently %senforcing)\n",
enforce ? "" : "not ");
parse_exclude();
- security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
+ security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
+ &loadpin_lsmid);
return 0;
}

diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index 87cbdc64d272..4e24ea3f7b7e 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -75,6 +75,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
};

+static struct lsm_id lockdown_lsmid __lsm_ro_after_init = {
+ .lsm = "lockdown",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static int __init lockdown_lsm_init(void)
{
#if defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY)
@@ -83,7 +88,7 @@ static int __init lockdown_lsm_init(void)
lock_kernel_down("Kernel configuration", LOCKDOWN_CONFIDENTIALITY_MAX);
#endif
security_add_hooks(lockdown_hooks, ARRAY_SIZE(lockdown_hooks),
- "lockdown");
+ &lockdown_lsmid);
return 0;
}

diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c
index 963f4ad9cb66..0c368950dc14 100644
--- a/security/safesetid/lsm.c
+++ b/security/safesetid/lsm.c
@@ -241,6 +241,11 @@ static int safesetid_task_fix_setgid(struct cred *new,
return -EACCES;
}

+static struct lsm_id safesetid_lsmid __lsm_ro_after_init = {
+ .lsm = "safesetid",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list safesetid_security_hooks[] = {
LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid),
LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid),
@@ -250,7 +255,8 @@ static struct security_hook_list safesetid_security_hooks[] = {
static int __init safesetid_security_init(void)
{
security_add_hooks(safesetid_security_hooks,
- ARRAY_SIZE(safesetid_security_hooks), "safesetid");
+ ARRAY_SIZE(safesetid_security_hooks),
+ &safesetid_lsmid);

/* Report that SafeSetID successfully initialized */
safesetid_initialized = 1;
diff --git a/security/security.c b/security/security.c
index 335c313a668d..5f1b281511f2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -344,6 +344,7 @@ static void __init ordered_lsm_init(void)
init_debug("sock blob size = %d\n", blob_sizes.lbs_sock);
init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
init_debug("task blob size = %d\n", blob_sizes.lbs_task);
+ init_debug("lsmblob size = %zu\n", sizeof(struct lsmblob));

/*
* Create any kmem_caches needed for blobs
@@ -471,21 +472,38 @@ static int lsm_append(const char *new, char **result)
return 0;
}

+/*
+ * Current index to use while initializing the lsmblob secid list.
+ */
+static int lsm_slot __lsm_ro_after_init;
+
/**
* security_add_hooks - Add a modules hooks to the hook lists.
* @hooks: the hooks to add
* @count: the number of hooks to add
- * @lsm: the name of the security module
+ * @lsmid: the identification information for the security module
*
* Each LSM has to register its hooks with the infrastructure.
+ * If the LSM is using hooks that export secids allocate a slot
+ * for it in the lsmblob.
*/
void __init security_add_hooks(struct security_hook_list *hooks, int count,
- char *lsm)
+ struct lsm_id *lsmid)
{
int i;

+ WARN_ON(!lsmid->slot || !lsmid->lsm);
+
+ if (lsmid->slot == LSMBLOB_NEEDED) {
+ if (lsm_slot >= LSMBLOB_ENTRIES)
+ panic("%s Too many LSMs registered.\n", __func__);
+ lsmid->slot = lsm_slot++;
+ init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
+ lsmid->slot);
+ }
+
for (i = 0; i < count; i++) {
- hooks[i].lsm = lsm;
+ hooks[i].lsmid = lsmid;
hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
}

@@ -494,7 +512,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
* and fix this up afterwards.
*/
if (slab_is_available()) {
- if (lsm_append(lsm, &lsm_names) < 0)
+ if (lsm_append(lsmid->lsm, &lsm_names) < 0)
panic("%s - Cannot get early memory.\n", __func__);
}
}
@@ -2070,7 +2088,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
struct security_hook_list *hp;

hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsm))
+ if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
continue;
return hp->hook.getprocattr(p, name, value);
}
@@ -2083,7 +2101,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
struct security_hook_list *hp;

hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsm))
+ if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
continue;
return hp->hook.setprocattr(name, value, size);
}
@@ -2576,7 +2594,24 @@ int security_key_getsecurity(struct key *key, char **_buffer)

int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
{
- return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+ struct security_hook_list *hp;
+ bool one_is_good = false;
+ int rc = 0;
+ int trc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ trc = hp->hook.audit_rule_init(field, op, rulestr,
+ &lsmrule[hp->lsmid->slot]);
+ if (trc == 0)
+ one_is_good = true;
+ else
+ rc = trc;
+ }
+ if (one_is_good)
+ return 0;
+ return rc;
}

int security_audit_rule_known(struct audit_krule *krule)
@@ -2584,14 +2619,31 @@ int security_audit_rule_known(struct audit_krule *krule)
return call_int_hook(audit_rule_known, 0, krule);
}

-void security_audit_rule_free(void *lsmrule)
+void security_audit_rule_free(void **lsmrule)
{
- call_void_hook(audit_rule_free, lsmrule);
+ struct security_hook_list *hp;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]);
+ }
}

-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule)
{
- return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+ struct security_hook_list *hp;
+ int rc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.audit_rule_match(secid, field, op,
+ &lsmrule[hp->lsmid->slot]);
+ if (rc)
+ return rc;
+ }
+ return 0;
}
#endif /* CONFIG_AUDIT */

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e2c4a1fd952f..f84b6c274a10 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7101,6 +7101,11 @@ static int selinux_perf_event_write(struct perf_event *event)
}
#endif

+static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+ .lsm = "selinux",
+ .slot = LSMBLOB_NEEDED
+};
+
/*
* IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
* 1. any hooks that don't belong to (2.) or (3.) below,
@@ -7414,7 +7419,8 @@ static __init int selinux_init(void)

hashtab_cache_init();

- security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
+ security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
+ &selinux_lsmid);

if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
panic("SELinux: Unable to register AVC netcache callback\n");
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 1ee0bf1493f6..5c10ad27be37 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4694,6 +4694,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_superblock = sizeof(struct superblock_smack),
};

+static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+ .lsm = "smack",
+ .slot = LSMBLOB_NEEDED
+};
+
static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
@@ -4893,7 +4898,7 @@ static __init int smack_init(void)
/*
* Register with LSM
*/
- security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
+ security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid);
smack_enabled = 1;

pr_info("Smack: Initializing.\n");
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
index b6a31901f289..e8f6bb9782c1 100644
--- a/security/tomoyo/tomoyo.c
+++ b/security/tomoyo/tomoyo.c
@@ -521,6 +521,11 @@ static void tomoyo_task_free(struct task_struct *task)
}
}

+static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = {
+ .lsm = "tomoyo",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
/*
* tomoyo_security_ops is a "struct security_operations" which is used for
* registering TOMOYO.
@@ -573,7 +578,8 @@ static int __init tomoyo_init(void)
struct tomoyo_task *s = tomoyo_task(current);

/* register ourselves with the security framework */
- security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
+ security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks),
+ &tomoyo_lsmid);
pr_info("TOMOYO Linux initialized\n");
s->domain_info = &tomoyo_kernel_domain;
atomic_inc(&tomoyo_kernel_domain.users);
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index 06e226166aab..a9639ea541f7 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -421,6 +421,11 @@ static int yama_ptrace_traceme(struct task_struct *parent)
return rc;
}

+static struct lsm_id yama_lsmid __lsm_ro_after_init = {
+ .lsm = "yama",
+ .slot = LSMBLOB_NOT_NEEDED
+};
+
static struct security_hook_list yama_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check),
LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme),
@@ -477,7 +482,7 @@ static inline void yama_init_sysctl(void) { }
static int __init yama_init(void)
{
pr_info("Yama: becoming mindful.\n");
- security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama");
+ security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), &yama_lsmid);
yama_init_sysctl();
return 0;
}
--
2.31.1

2021-07-22 00:54:38

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 04/25] IMA: avoid label collisions with stacked LSMs

Integrity measurement may filter on security module information
and needs to be clear in the case of multiple active security
modules which applies. Provide a boot option ima_rules_lsm= to
allow the user to specify an active securty module to apply
filters to. If not specified, use the first registered module
that supports the audit_rule_match() LSM hook. Allow the user
to specify in the IMA policy an lsm= option to specify the
security module to use for a particular rule.

Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
To: Mimi Zohar <[email protected]>
To: [email protected]
---
Documentation/ABI/testing/ima_policy | 8 ++-
security/integrity/ima/ima_policy.c | 79 ++++++++++++++++++++--------
2 files changed, 64 insertions(+), 23 deletions(-)

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 070779e8d836..84dd19bc4344 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -25,7 +25,7 @@ Description:
base: [[func=] [mask=] [fsmagic=] [fsuuid=] [uid=]
[euid=] [fowner=] [fsname=]]
lsm: [[subj_user=] [subj_role=] [subj_type=]
- [obj_user=] [obj_role=] [obj_type=]]
+ [obj_user=] [obj_role=] [obj_type=] [lsm=]]
option: [[appraise_type=]] [template=] [permit_directio]
[appraise_flag=] [keyrings=]
base:
@@ -117,6 +117,12 @@ Description:

measure subj_user=_ func=FILE_CHECK mask=MAY_READ

+ It is possible to explicitly specify which security
+ module a rule applies to using lsm=. If the security
+ modules specified is not active on the system the rule
+ will be rejected. If lsm= is not specified the first
+ security module registered on the system will be assumed.
+
Example of measure rules using alternate PCRs::

measure func=KEXEC_KERNEL_CHECK pcr=4
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 5c40677e881c..008a043335d4 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -79,8 +79,9 @@ struct ima_rule_entry {
bool (*uid_op)(kuid_t, kuid_t); /* Handlers for operators */
bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
int pcr;
+ int which_lsm; /* which of the rules to use */
struct {
- void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */
+ void *rule; /* LSM file metadata specific */
char *args_p; /* audit value */
int type; /* audit type */
} lsm[MAX_LSM_RULES];
@@ -92,17 +93,17 @@ struct ima_rule_entry {

/**
* ima_lsm_isset - Is a rule set for any of the active security modules
- * @rules: The set of IMA rules to check
+ * @entry: the rule entry to examine
+ * @lsm_rule: the specific rule type in question
*
- * If a rule is set for any LSM return true, otherwise return false.
+ * If a rule is set return true, otherwise return false.
*/
-static inline bool ima_lsm_isset(void *rules[])
+static inline bool ima_lsm_isset(struct ima_rule_entry *entry, int lsm_rule)
{
- int i;
-
- for (i = 0; i < LSMBLOB_ENTRIES; i++)
- if (rules[i])
- return true;
+ if (lsm_rule < 0 || lsm_rule > MAX_LSM_RULES)
+ return false;
+ if (entry->lsm[lsm_rule].rule)
+ return true;
return false;
}

@@ -282,6 +283,20 @@ static int __init default_appraise_policy_setup(char *str)
}
__setup("ima_appraise_tcb", default_appraise_policy_setup);

+static int ima_rules_lsm __ro_after_init;
+
+static int __init ima_rules_lsm_init(char *str)
+{
+ ima_rules_lsm = lsm_name_to_slot(str);
+ if (ima_rules_lsm < 0) {
+ ima_rules_lsm = 0;
+ pr_err("rule lsm \"%s\" not registered", str);
+ }
+
+ return 1;
+}
+__setup("ima_rules_lsm=", ima_rules_lsm_init);
+
static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
{
struct ima_rule_opt_list *opt_list;
@@ -351,11 +366,10 @@ static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list)
static void ima_lsm_free_rule(struct ima_rule_entry *entry)
{
int i;
- int r;

for (i = 0; i < MAX_LSM_RULES; i++) {
- for (r = 0; r < LSMBLOB_ENTRIES; r++)
- ima_filter_rule_free(entry->lsm[i].rules[r]);
+ if (entry->lsm[i].rule)
+ ima_filter_rule_free(entry->lsm[i].rule);
kfree(entry->lsm[i].args_p);
}
}
@@ -406,8 +420,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)

ima_filter_rule_init(nentry->lsm[i].type, Audit_equal,
nentry->lsm[i].args_p,
- &nentry->lsm[i].rules[0]);
- if (!ima_lsm_isset(nentry->lsm[i].rules))
+ &nentry->lsm[i].rule);
+ if (!ima_lsm_isset(nentry, i))
pr_warn("rule for LSM \'%s\' is undefined\n",
nentry->lsm[i].args_p);
}
@@ -596,7 +610,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
int rc = 0;
u32 osid;

- if (!ima_lsm_isset(rule->lsm[i].rules)) {
+ if (!ima_lsm_isset(rule, i)) {
if (!rule->lsm[i].args_p)
continue;
else
@@ -609,14 +623,14 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
security_inode_getsecid(inode, &osid);
rc = ima_filter_rule_match(osid, rule->lsm[i].type,
Audit_equal,
- rule->lsm[i].rules);
+ rule->lsm[i].rule);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
rc = ima_filter_rule_match(secid, rule->lsm[i].type,
Audit_equal,
- rule->lsm[i].rules);
+ rule->lsm[i].rule);
break;
default:
break;
@@ -966,7 +980,7 @@ enum {
Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
Opt_appraise_type, Opt_appraise_flag,
Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
- Opt_label, Opt_err
+ Opt_lsm, Opt_label, Opt_err
};

static const match_table_t policy_tokens = {
@@ -1004,6 +1018,7 @@ static const match_table_t policy_tokens = {
{Opt_template, "template=%s"},
{Opt_keyrings, "keyrings=%s"},
{Opt_label, "label=%s"},
+ {Opt_lsm, "lsm=%s"},
{Opt_err, NULL}
};

@@ -1012,7 +1027,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
{
int result;

- if (ima_lsm_isset(entry->lsm[lsm_rule].rules))
+ if (ima_lsm_isset(entry, lsm_rule))
return -EINVAL;

entry->lsm[lsm_rule].args_p = match_strdup(args);
@@ -1022,8 +1037,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
entry->lsm[lsm_rule].type = audit_type;
result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal,
entry->lsm[lsm_rule].args_p,
- &entry->lsm[lsm_rule].rules[0]);
- if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) {
+ &entry->lsm[lsm_rule].rule);
+ if (!ima_lsm_isset(entry, lsm_rule)) {
pr_warn("rule for LSM \'%s\' is undefined\n",
entry->lsm[lsm_rule].args_p);

@@ -1561,6 +1576,19 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
&(template_desc->num_fields));
entry->template = template_desc;
break;
+ case Opt_lsm:
+ result = lsm_name_to_slot(args[0].from);
+ if (result == LSMBLOB_INVALID) {
+ int i;
+
+ for (i = 0; i < MAX_LSM_RULES; i++)
+ entry->lsm[i].args_p = NULL;
+ result = -EINVAL;
+ break;
+ }
+ entry->which_lsm = result;
+ result = 0;
+ break;
case Opt_err:
ima_log_string(ab, "UNKNOWN", p);
result = -EINVAL;
@@ -1597,6 +1625,7 @@ ssize_t ima_parse_add_rule(char *rule)
struct ima_rule_entry *entry;
ssize_t result, len;
int audit_info = 0;
+ int i;

p = strsep(&rule, "\n");
len = strlen(p) + 1;
@@ -1614,6 +1643,9 @@ ssize_t ima_parse_add_rule(char *rule)

INIT_LIST_HEAD(&entry->list);

+ for (i = 0; i < MAX_LSM_RULES; i++)
+ entry->which_lsm = ima_rules_lsm;
+
result = ima_parse_rule(p, entry);
if (result) {
ima_free_rule(entry);
@@ -1830,7 +1862,7 @@ int ima_policy_show(struct seq_file *m, void *v)
}

for (i = 0; i < MAX_LSM_RULES; i++) {
- if (ima_lsm_isset(entry->lsm[i].rules)) {
+ if (ima_lsm_isset(entry, i)) {
switch (i) {
case LSM_OBJ_USER:
seq_printf(m, pt(Opt_obj_user),
@@ -1872,6 +1904,9 @@ int ima_policy_show(struct seq_file *m, void *v)
seq_puts(m, "appraise_flag=check_blacklist ");
if (entry->flags & IMA_PERMIT_DIRECTIO)
seq_puts(m, "permit_directio ");
+ if (entry->which_lsm >= 0)
+ seq_printf(m, pt(Opt_lsm),
+ lsm_slot_to_name(entry->which_lsm));
rcu_read_unlock();
seq_puts(m, "\n");
return 0;
--
2.31.1

2021-07-22 00:55:09

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 03/25] LSM: provide lsm name and id slot mappings

Provide interfaces to map LSM slot numbers and LSM names.
Update the LSM registration code to save this information.

Acked-by: Paul Moore <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
---
include/linux/security.h | 4 ++++
security/security.c | 45 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+)

diff --git a/include/linux/security.h b/include/linux/security.h
index 7655bfce4b96..b641b5b96860 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -192,6 +192,10 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
return !memcmp(bloba, blobb, sizeof(*bloba));
}

+/* Map lsm names to blob slot numbers */
+extern int lsm_name_to_slot(char *name);
+extern const char *lsm_slot_to_name(int slot);
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
diff --git a/security/security.c b/security/security.c
index 5f1b281511f2..3da6cb8f9d76 100644
--- a/security/security.c
+++ b/security/security.c
@@ -476,6 +476,50 @@ static int lsm_append(const char *new, char **result)
* Current index to use while initializing the lsmblob secid list.
*/
static int lsm_slot __lsm_ro_after_init;
+static struct lsm_id *lsm_slotlist[LSMBLOB_ENTRIES] __lsm_ro_after_init;
+
+/**
+ * lsm_name_to_slot - Report the slot number for a security module
+ * @name: name of the security module
+ *
+ * Look up the slot number for the named security module.
+ * Returns the slot number or LSMBLOB_INVALID if @name is not
+ * a registered security module name.
+ */
+int lsm_name_to_slot(char *name)
+{
+ int i;
+
+ for (i = 0; i < lsm_slot; i++)
+ if (strcmp(lsm_slotlist[i]->lsm, name) == 0)
+ return i;
+
+ return LSMBLOB_INVALID;
+}
+
+/**
+ * lsm_slot_to_name - Get the name of the security module in a slot
+ * @slot: index into the interface LSM slot list.
+ *
+ * Provide the name of the security module associated with
+ * a interface LSM slot.
+ *
+ * If @slot is LSMBLOB_INVALID return the value
+ * for slot 0 if it has been set, otherwise NULL.
+ *
+ * Returns a pointer to the name string or NULL.
+ */
+const char *lsm_slot_to_name(int slot)
+{
+ if (slot == LSMBLOB_INVALID)
+ slot = 0;
+ else if (slot >= LSMBLOB_ENTRIES || slot < 0)
+ return NULL;
+
+ if (lsm_slotlist[slot] == NULL)
+ return NULL;
+ return lsm_slotlist[slot]->lsm;
+}

/**
* security_add_hooks - Add a modules hooks to the hook lists.
@@ -497,6 +541,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
if (lsmid->slot == LSMBLOB_NEEDED) {
if (lsm_slot >= LSMBLOB_ENTRIES)
panic("%s Too many LSMs registered.\n", __func__);
+ lsm_slotlist[lsm_slot] = lsmid;
lsmid->slot = lsm_slot++;
init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
lsmid->slot);
--
2.31.1

2021-07-22 00:56:33

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 06/25] LSM: Use lsmblob in security_kernel_act_as

Change the security_kernel_act_as interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change its only caller, set_security_override,
to do the same. Change that one's only caller,
set_security_override_from_ctx, to call it with the new
parameter type.

The security module hook is unchanged, still taking a secid.
The infrastructure passes the correct entry from the lsmblob.
lsmblob_init() is used to fill the lsmblob structure, however
this will be removed later in the series when security_secctx_to_secid()
is updated to provide a lsmblob instead of a secid.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
To: David Howells <[email protected]>
---
include/linux/cred.h | 3 ++-
include/linux/security.h | 5 +++--
kernel/cred.c | 10 ++++++----
security/security.c | 14 ++++++++++++--
4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/include/linux/cred.h b/include/linux/cred.h
index fcbc6885cc09..eb02e8514239 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -18,6 +18,7 @@

struct cred;
struct inode;
+struct lsmblob;

/*
* COW Supplementary groups list
@@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *);
extern void revert_creds(const struct cred *);
extern struct cred *prepare_kernel_cred(struct task_struct *);
extern int change_create_files_as(struct cred *, struct inode *);
-extern int set_security_override(struct cred *, u32);
+extern int set_security_override(struct cred *, struct lsmblob *);
extern int set_security_override_from_ctx(struct cred *, const char *);
extern int set_create_files_as(struct cred *, struct inode *);
extern int cred_fscmp(const struct cred *, const struct cred *);
diff --git a/include/linux/security.h b/include/linux/security.h
index 8290f6263b6d..332df8a1cd4d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -461,7 +461,7 @@ void security_cred_free(struct cred *cred);
int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
void security_transfer_creds(struct cred *new, const struct cred *old);
void security_cred_getsecid(const struct cred *c, u32 *secid);
-int security_kernel_act_as(struct cred *new, u32 secid);
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(char *kmod_name);
int security_kernel_load_data(enum kernel_load_data_id id, bool contents);
@@ -1103,7 +1103,8 @@ static inline void security_transfer_creds(struct cred *new,
{
}

-static inline int security_kernel_act_as(struct cred *cred, u32 secid)
+static inline int security_kernel_act_as(struct cred *cred,
+ struct lsmblob *blob)
{
return 0;
}
diff --git a/kernel/cred.c b/kernel/cred.c
index e6fd2b3fc31f..ea36ec6e1ad8 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -774,14 +774,14 @@ EXPORT_SYMBOL(prepare_kernel_cred);
/**
* set_security_override - Set the security ID in a set of credentials
* @new: The credentials to alter
- * @secid: The LSM security ID to set
+ * @blob: The LSM security information to set
*
* Set the LSM security ID in a set of credentials so that the subjective
* security is overridden when an alternative set of credentials is used.
*/
-int set_security_override(struct cred *new, u32 secid)
+int set_security_override(struct cred *new, struct lsmblob *blob)
{
- return security_kernel_act_as(new, secid);
+ return security_kernel_act_as(new, blob);
}
EXPORT_SYMBOL(set_security_override);

@@ -797,6 +797,7 @@ EXPORT_SYMBOL(set_security_override);
*/
int set_security_override_from_ctx(struct cred *new, const char *secctx)
{
+ struct lsmblob blob;
u32 secid;
int ret;

@@ -804,7 +805,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx)
if (ret < 0)
return ret;

- return set_security_override(new, secid);
+ lsmblob_init(&blob, secid);
+ return set_security_override(new, &blob);
}
EXPORT_SYMBOL(set_security_override_from_ctx);

diff --git a/security/security.c b/security/security.c
index 3c035faa2c37..69474918be8b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1798,9 +1798,19 @@ void security_cred_getsecid(const struct cred *c, u32 *secid)
}
EXPORT_SYMBOL(security_cred_getsecid);

-int security_kernel_act_as(struct cred *new, u32 secid)
+int security_kernel_act_as(struct cred *new, struct lsmblob *blob)
{
- return call_int_hook(kernel_act_as, 0, new, secid);
+ struct security_hook_list *hp;
+ int rc;
+
+ hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.kernel_act_as(new, blob->secid[hp->lsmid->slot]);
+ if (rc != 0)
+ return rc;
+ }
+ return 0;
}

int security_kernel_create_files_as(struct cred *new, struct inode *inode)
--
2.31.1

2021-07-22 00:57:54

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 05/25] LSM: Use lsmblob in security_audit_rule_match

Change the secid parameter of security_audit_rule_match
to a lsmblob structure pointer. Pass the entry from the
lsmblob structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsmblob instead of a u32. The scaffolding function lsmblob_init()
fills the blob with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the blob structure later in the series.
At the point the use of lsmblob_init() is dropped.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
To: Mimi Zohar <[email protected]>
---
include/linux/security.h | 7 ++++---
kernel/auditfilter.c | 6 ++++--
kernel/auditsc.c | 16 +++++++++++-----
security/integrity/ima/ima.h | 4 ++--
security/integrity/ima/ima_policy.c | 7 +++++--
security/security.c | 10 ++++++++--
6 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index b641b5b96860..8290f6263b6d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1944,7 +1944,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
#ifdef CONFIG_SECURITY
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule);
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+ void **lsmrule);
void security_audit_rule_free(void **lsmrule);

#else
@@ -1960,8 +1961,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
return 0;
}

-static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
- void **lsmrule)
+static inline int security_audit_rule_match(struct lsmblob *blob, u32 field,
+ u32 op, void **lsmrule)
{
return 0;
}
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a2340e81cfa7..6a04d762d272 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1331,6 +1331,7 @@ int audit_filter(int msgtype, unsigned int listtype)
struct audit_field *f = &e->rule.fields[i];
pid_t pid;
u32 sid;
+ struct lsmblob blob;

switch (f->type) {
case AUDIT_PID:
@@ -1362,8 +1363,9 @@ int audit_filter(int msgtype, unsigned int listtype)
if (f->lsm_isset) {
security_task_getsecid_subj(current,
&sid);
- result = security_audit_rule_match(sid,
- f->type, f->op,
+ lsmblob_init(&blob, sid);
+ result = security_audit_rule_match(
+ &blob, f->type, f->op,
f->lsm_rules);
}
break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index acbd896f54a5..447614b7a50b 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -478,6 +478,7 @@ static int audit_filter_rules(struct task_struct *tsk,
const struct cred *cred;
int i, need_sid = 1;
u32 sid;
+ struct lsmblob blob;
unsigned int sessionid;

cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
@@ -676,8 +677,10 @@ static int audit_filter_rules(struct task_struct *tsk,
security_task_getsecid_subj(tsk, &sid);
need_sid = 0;
}
- result = security_audit_rule_match(sid, f->type,
- f->op, f->lsm_rules);
+ lsmblob_init(&blob, sid);
+ result = security_audit_rule_match(&blob,
+ f->type, f->op,
+ f->lsm_rules);
}
break;
case AUDIT_OBJ_USER:
@@ -690,15 +693,17 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_isset) {
/* Find files that match */
if (name) {
+ lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
- name->osid,
+ &blob,
f->type,
f->op,
f->lsm_rules);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
+ lsmblob_init(&blob, name->osid);
if (security_audit_rule_match(
- n->osid,
+ &blob,
f->type,
f->op,
f->lsm_rules)) {
@@ -710,7 +715,8 @@ static int audit_filter_rules(struct task_struct *tsk,
/* Find ipc objects that match */
if (!ctx || ctx->type != AUDIT_IPC)
break;
- if (security_audit_rule_match(ctx->ipc.osid,
+ lsmblob_init(&blob, ctx->ipc.osid);
+ if (security_audit_rule_match(&blob,
f->type, f->op,
f->lsm_rules))
++result;
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f0e448ed1f9f..55f3bd4f0b01 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -433,8 +433,8 @@ static inline void ima_filter_rule_free(void *lsmrule)
{
}

-static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+static inline int ima_filter_rule_match(struct lsmblob *blob, u32 field,
+ u32 op, void *lsmrule)
{
return -EINVAL;
}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 008a043335d4..af612a42eebe 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -609,6 +609,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid;
+ struct lsmblob lsmdata;

if (!ima_lsm_isset(rule, i)) {
if (!rule->lsm[i].args_p)
@@ -621,14 +622,16 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
security_inode_getsecid(inode, &osid);
- rc = ima_filter_rule_match(osid, rule->lsm[i].type,
+ lsmblob_init(&lsmdata, osid);
+ rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- rc = ima_filter_rule_match(secid, rule->lsm[i].type,
+ lsmblob_init(&lsmdata, secid);
+ rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
break;
diff --git a/security/security.c b/security/security.c
index 3da6cb8f9d76..3c035faa2c37 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2671,11 +2671,14 @@ void security_audit_rule_free(void **lsmrule)
hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
+ if (lsmrule[hp->lsmid->slot] == NULL)
+ continue;
hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]);
}
}

-int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule)
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
+ void **lsmrule)
{
struct security_hook_list *hp;
int rc;
@@ -2683,7 +2686,10 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule)
hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- rc = hp->hook.audit_rule_match(secid, field, op,
+ if (lsmrule[hp->lsmid->slot] == NULL)
+ continue;
+ rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+ field, op,
&lsmrule[hp->lsmid->slot]);
if (rc)
return rc;
--
2.31.1

2021-07-22 00:57:55

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 07/25] LSM: Use lsmblob in security_secctx_to_secid

Change the security_secctx_to_secid interface to use a lsmblob
structure in place of the single u32 secid in support of
module stacking. Change its callers to do the same.

The security module hook is unchanged, still passing back a secid.
The infrastructure passes the correct entry from the lsmblob.

Acked-by: Paul Moore <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
To: Pablo Neira Ayuso <[email protected]>
---
include/linux/security.h | 26 ++++++++++++++++++--
kernel/cred.c | 4 +---
net/netfilter/nft_meta.c | 10 ++++----
net/netfilter/xt_SECMARK.c | 7 +++++-
net/netlabel/netlabel_unlabeled.c | 23 +++++++++++-------
security/security.c | 40 ++++++++++++++++++++++++++-----
6 files changed, 85 insertions(+), 25 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 332df8a1cd4d..986a8f4bcd54 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -196,6 +196,27 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
extern int lsm_name_to_slot(char *name);
extern const char *lsm_slot_to_name(int slot);

+/**
+ * lsmblob_value - find the first non-zero value in an lsmblob structure.
+ * @blob: Pointer to the data
+ *
+ * This needs to be used with extreme caution, as the cases where
+ * it is appropriate are rare.
+ *
+ * Return the first secid value set in the lsmblob.
+ * There should only be one.
+ */
+static inline u32 lsmblob_value(const struct lsmblob *blob)
+{
+ int i;
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++)
+ if (blob->secid[i])
+ return blob->secid[i];
+
+ return 0;
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
@@ -527,7 +548,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+ struct lsmblob *blob);
void security_release_secctx(char *secdata, u32 seclen);
void security_inode_invalidate_secctx(struct inode *inode);
int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
@@ -1382,7 +1404,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle

static inline int security_secctx_to_secid(const char *secdata,
u32 seclen,
- u32 *secid)
+ struct lsmblob *blob)
{
return -EOPNOTSUPP;
}
diff --git a/kernel/cred.c b/kernel/cred.c
index ea36ec6e1ad8..38b00a1390f4 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -798,14 +798,12 @@ EXPORT_SYMBOL(set_security_override);
int set_security_override_from_ctx(struct cred *new, const char *secctx)
{
struct lsmblob blob;
- u32 secid;
int ret;

- ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
+ ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
if (ret < 0)
return ret;

- lsmblob_init(&blob, secid);
return set_security_override(new, &blob);
}
EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index a7e01e9952f1..f9448e81798e 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -809,21 +809,21 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {

static int nft_secmark_compute_secid(struct nft_secmark *priv)
{
- u32 tmp_secid = 0;
+ struct lsmblob blob;
int err;

- err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
+ err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
if (err)
return err;

- if (!tmp_secid)
+ if (!lsmblob_is_set(&blob))
return -ENOENT;

- err = security_secmark_relabel_packet(tmp_secid);
+ err = security_secmark_relabel_packet(lsmblob_value(&blob));
if (err)
return err;

- priv->secid = tmp_secid;
+ priv->secid = lsmblob_value(&blob);
return 0;
}

diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index 498a0bf6f044..87ca3a537d1c 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -42,13 +42,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_secmark_target_info_v1 *info)

static int checkentry_lsm(struct xt_secmark_target_info_v1 *info)
{
+ struct lsmblob blob;
int err;

info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
info->secid = 0;

err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
- &info->secid);
+ &blob);
if (err) {
if (err == -EINVAL)
pr_info_ratelimited("invalid security context \'%s\'\n",
@@ -56,6 +57,10 @@ static int checkentry_lsm(struct xt_secmark_target_info_v1 *info)
return err;
}

+ /* xt_secmark_target_info can't be changed to use lsmblobs because
+ * it is exposed as an API. Use lsmblob_value() to get the one
+ * value that got set by security_secctx_to_secid(). */
+ info->secid = lsmblob_value(&blob);
if (!info->secid) {
pr_info_ratelimited("unable to map security context \'%s\'\n",
info->secctx);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 2483df0bbd7c..c29a8d7a7070 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -882,7 +882,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
void *addr;
void *mask;
u32 addr_len;
- u32 secid;
+ struct lsmblob blob;
struct netlbl_audit audit_info;

/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -906,13 +906,18 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
ret_val = security_secctx_to_secid(
nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
- &secid);
+ &blob);
if (ret_val != 0)
return ret_val;

+ /* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
+ * instead of a u32 later in this patch set. security_secctx_to_secid()
+ * will only be setting one entry in the lsmblob struct, so it is
+ * safe to use lsmblob_value() to get that one value. */
+
return netlbl_unlhsh_add(&init_net,
- dev_name, addr, mask, addr_len, secid,
- &audit_info);
+ dev_name, addr, mask, addr_len,
+ lsmblob_value(&blob), &audit_info);
}

/**
@@ -933,7 +938,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
void *addr;
void *mask;
u32 addr_len;
- u32 secid;
+ struct lsmblob blob;
struct netlbl_audit audit_info;

/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -955,13 +960,15 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
ret_val = security_secctx_to_secid(
nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
- &secid);
+ &blob);
if (ret_val != 0)
return ret_val;

+ /* security_secctx_to_secid() will only put one secid into the lsmblob
+ * so it's safe to use lsmblob_value() to get the secid. */
return netlbl_unlhsh_add(&init_net,
- NULL, addr, mask, addr_len, secid,
- &audit_info);
+ NULL, addr, mask, addr_len,
+ lsmblob_value(&blob), &audit_info);
}

/**
diff --git a/security/security.c b/security/security.c
index 69474918be8b..1621a28bf9c4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2193,10 +2193,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
}
EXPORT_SYMBOL(security_secid_to_secctx);

-int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+int security_secctx_to_secid(const char *secdata, u32 seclen,
+ struct lsmblob *blob)
{
- *secid = 0;
- return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
+ struct security_hook_list *hp;
+ int rc;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.secctx_to_secid(secdata, seclen,
+ &blob->secid[hp->lsmid->slot]);
+ if (rc != 0)
+ return rc;
+ }
+ return 0;
}
EXPORT_SYMBOL(security_secctx_to_secid);

@@ -2347,10 +2359,26 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
optval, optlen, len);
}

-int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
+int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
+ u32 *secid)
{
- return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
- skb, secid);
+ struct security_hook_list *hp;
+ int rc = -ENOPROTOOPT;
+
+ /*
+ * Only one security module should provide a real hook for
+ * this. A stub or bypass like is used in BPF should either
+ * (somehow) leave rc unaltered or return -ENOPROTOOPT.
+ */
+ hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
+ list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.socket_getpeersec_dgram(sock, skb, secid);
+ if (rc != -ENOPROTOOPT)
+ break;
+ }
+ return rc;
}
EXPORT_SYMBOL(security_socket_getpeersec_dgram);

--
2.31.1

2021-07-22 00:58:02

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 08/25] LSM: Use lsmblob in security_secid_to_secctx

Change security_secid_to_secctx() to take a lsmblob as input
instead of a u32 secid. It will then call the LSM hooks
using the lsmblob element allocated for that module. The
callers have been updated as well. This allows for the
possibility that more than one module may be called upon
to translate a secid to a string, as can occur in the
audit code.

Acked-by: Paul Moore <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
To: Pablo Neira Ayuso <[email protected]>
---
drivers/android/binder.c | 12 +++++++++-
include/linux/security.h | 5 +++--
include/net/scm.h | 7 +++++-
kernel/audit.c | 20 +++++++++++++++--
kernel/auditsc.c | 27 ++++++++++++++++++----
net/ipv4/ip_sockglue.c | 4 +++-
net/netfilter/nf_conntrack_netlink.c | 14 ++++++++++--
net/netfilter/nf_conntrack_standalone.c | 4 +++-
net/netfilter/nfnetlink_queue.c | 11 +++++++--
net/netlabel/netlabel_unlabeled.c | 30 +++++++++++++++++++++----
net/netlabel/netlabel_user.c | 6 ++---
security/security.c | 11 +++++----
12 files changed, 122 insertions(+), 29 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index bcec598b89f2..3e97a6de5e80 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2711,6 +2711,7 @@ static void binder_transaction(struct binder_proc *proc,

if (target_node && target_node->txn_security_ctx) {
u32 secid;
+ struct lsmblob blob;
size_t added_size;

/*
@@ -2723,7 +2724,16 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &secid);
- ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
+ /*
+ * Later in this patch set security_task_getsecid() will
+ * provide a lsmblob instead of a secid. lsmblob_init
+ * is used to ensure that all the secids in the lsmblob
+ * get the value returned from security_task_getsecid(),
+ * which means that the one expected by
+ * security_secid_to_secctx() will be set.
+ */
+ lsmblob_init(&blob, secid);
+ ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
diff --git a/include/linux/security.h b/include/linux/security.h
index 986a8f4bcd54..ef33be59998e 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -547,7 +547,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(char *secdata, u32 seclen);
@@ -1397,7 +1397,8 @@ static inline int security_ismaclabel(const char *name)
return 0;
}

-static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+static inline int security_secid_to_secctx(struct lsmblob *blob,
+ char **secdata, u32 *seclen)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/scm.h b/include/net/scm.h
index 1ce365f4c256..23a35ff1b3f2 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -92,12 +92,17 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
#ifdef CONFIG_SECURITY_NETWORK
static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
{
+ struct lsmblob lb;
char *secdata;
u32 seclen;
int err;

if (test_bit(SOCK_PASSSEC, &sock->flags)) {
- err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+ /* There can only be one security module using the secid,
+ * and the infrastructure will know which it is.
+ */
+ lsmblob_init(&lb, scm->secid);
+ err = security_secid_to_secctx(&lb, &secdata, &seclen);

if (!err) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
diff --git a/kernel/audit.c b/kernel/audit.c
index 121d37e700a6..22286163e93e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1442,7 +1442,16 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_SIGNAL_INFO:
len = 0;
if (audit_sig_sid) {
- err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
+ struct lsmblob blob;
+
+ /*
+ * lsmblob_init sets all values in the lsmblob
+ * to audit_sig_sid. This is temporary until
+ * audit_sig_sid is converted to a lsmblob, which
+ * happens later in this patch set.
+ */
+ lsmblob_init(&blob, audit_sig_sid);
+ err = security_secid_to_secctx(&blob, &ctx, &len);
if (err)
return err;
}
@@ -2131,12 +2140,19 @@ int audit_log_task_context(struct audit_buffer *ab)
unsigned len;
int error;
u32 sid;
+ struct lsmblob blob;

security_task_getsecid_subj(current, &sid);
if (!sid)
return 0;

- error = security_secid_to_secctx(sid, &ctx, &len);
+ /*
+ * lsmblob_init sets all values in the lsmblob to sid.
+ * This is temporary until security_task_getsecid is converted
+ * to use a lsmblob, which happens later in this patch set.
+ */
+ lsmblob_init(&blob, sid);
+ error = security_secid_to_secctx(&blob, &ctx, &len);
if (error) {
if (error != -EINVAL)
goto error_path;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 447614b7a50b..df8a57c5355d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -677,6 +677,13 @@ static int audit_filter_rules(struct task_struct *tsk,
security_task_getsecid_subj(tsk, &sid);
need_sid = 0;
}
+ /*
+ * lsmblob_init sets all values in the lsmblob
+ * to sid. This is temporary until
+ * security_task_getsecid() is converted to
+ * provide a lsmblob, which happens later in
+ * this patch set.
+ */
lsmblob_init(&blob, sid);
result = security_audit_rule_match(&blob,
f->type, f->op,
@@ -693,6 +700,13 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_isset) {
/* Find files that match */
if (name) {
+ /*
+ * lsmblob_init sets all values in the
+ * lsmblob to sid. This is temporary
+ * until name->osid is converted to a
+ * lsmblob, which happens later in
+ * this patch set.
+ */
lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
&blob,
@@ -999,6 +1013,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
char *ctx = NULL;
u32 len;
int rc = 0;
+ struct lsmblob blob;

ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
if (!ab)
@@ -1008,7 +1023,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (sid) {
- if (security_secid_to_secctx(sid, &ctx, &len)) {
+ lsmblob_init(&blob, sid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1252,8 +1268,10 @@ static void show_special(struct audit_context *context, int *call_panic)
if (osid) {
char *ctx = NULL;
u32 len;
+ struct lsmblob blob;

- if (security_secid_to_secctx(osid, &ctx, &len)) {
+ lsmblob_init(&blob, osid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
@@ -1408,9 +1426,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
if (n->osid != 0) {
char *ctx = NULL;
u32 len;
+ struct lsmblob blob;

- if (security_secid_to_secctx(
- n->osid, &ctx, &len)) {
+ lsmblob_init(&blob, n->osid);
+ if (security_secid_to_secctx(&blob, &ctx, &len)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ec6036713e2c..2f089733ada7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,

static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
{
+ struct lsmblob lb;
char *secdata;
u32 seclen, secid;
int err;
@@ -138,7 +139,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
if (err)
return;

- err = security_secid_to_secctx(secid, &secdata, &seclen);
+ lsmblob_init(&lb, secid);
+ err = security_secid_to_secctx(&lb, &secdata, &seclen);
if (err)
return;

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index e81af33b233b..9bf1f5460681 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -341,8 +341,13 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
struct nlattr *nest_secctx;
int len, ret;
char *secctx;
+ struct lsmblob blob;

- ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+ /* lsmblob_init() puts ct->secmark into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, &secctx, &len);
if (ret)
return 0;

@@ -650,8 +655,13 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
{
#ifdef CONFIG_NF_CONNTRACK_SECMARK
int len, ret;
+ struct lsmblob blob;

- ret = security_secid_to_secctx(ct->secmark, NULL, &len);
+ /* lsmblob_init() puts ct->secmark into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, NULL, &len);
if (ret)
return 0;

diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 214d9f9e499b..89b6f5ebcfc4 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
int ret;
u32 len;
char *secctx;
+ struct lsmblob blob;

- ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
+ lsmblob_init(&blob, ct->secmark);
+ ret = security_secid_to_secctx(&blob, &secctx, &len);
if (ret)
return;

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index f774de0fc24f..a781e757d593 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -305,13 +305,20 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
{
u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
+ struct lsmblob blob;
+
if (!skb || !sk_fullsock(skb->sk))
return 0;

read_lock_bh(&skb->sk->sk_callback_lock);

- if (skb->secmark)
- security_secid_to_secctx(skb->secmark, secdata, &seclen);
+ if (skb->secmark) {
+ /* lsmblob_init() puts ct->secmark into all of the secids in
+ * blob. security_secid_to_secctx() will know which security
+ * module to use to create the secctx. */
+ lsmblob_init(&blob, skb->secmark);
+ security_secid_to_secctx(&blob, secdata, &seclen);
+ }

read_unlock_bh(&skb->sk->sk_callback_lock);
#endif
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index c29a8d7a7070..5cbbc469ac7c 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -376,6 +376,7 @@ int netlbl_unlhsh_add(struct net *net,
struct audit_buffer *audit_buf = NULL;
char *secctx = NULL;
u32 secctx_len;
+ struct lsmblob blob;

if (addr_len != sizeof(struct in_addr) &&
addr_len != sizeof(struct in6_addr))
@@ -438,7 +439,11 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- if (security_secid_to_secctx(secid,
+ /* lsmblob_init() puts secid into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, secid);
+ if (security_secid_to_secctx(&blob,
&secctx,
&secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
@@ -475,6 +480,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct net_device *dev;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -494,8 +500,13 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
addr->s_addr, mask->s_addr);
if (dev != NULL)
dev_put(dev);
+ /* lsmblob_init() puts entry->secid into all of the secids
+ * in blob. security_secid_to_secctx() will know which
+ * security module to use to create the secctx. */
+ if (entry != NULL)
+ lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(entry->secid,
+ security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
security_release_secctx(secctx, secctx_len);
@@ -537,6 +548,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct net_device *dev;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -555,8 +567,13 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
addr, mask);
if (dev != NULL)
dev_put(dev);
+ /* lsmblob_init() puts entry->secid into all of the secids
+ * in blob. security_secid_to_secctx() will know which
+ * security module to use to create the secctx. */
+ if (entry != NULL)
+ lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(entry->secid,
+ security_secid_to_secctx(&blob,
&secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " sec_obj=%s", secctx);
security_release_secctx(secctx, secctx_len);
@@ -1082,6 +1099,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
u32 secid;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;

data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1136,7 +1154,11 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
secid = addr6->secid;
}

- ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
+ /* lsmblob_init() secid into all of the secids in blob.
+ * security_secid_to_secctx() will know which security module
+ * to use to create the secctx. */
+ lsmblob_init(&blob, secid);
+ ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 3ed4fea2a2de..893301ae0131 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -86,6 +86,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
struct audit_buffer *audit_buf;
char *secctx;
u32 secctx_len;
+ struct lsmblob blob;

if (audit_enabled == AUDIT_OFF)
return NULL;
@@ -98,10 +99,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
from_kuid(&init_user_ns, audit_info->loginuid),
audit_info->sessionid);

+ lsmblob_init(&blob, audit_info->secid);
if (audit_info->secid != 0 &&
- security_secid_to_secctx(audit_info->secid,
- &secctx,
- &secctx_len) == 0) {
+ security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
audit_log_format(audit_buf, " subj=%s", secctx);
security_release_secctx(secctx, secctx_len);
}
diff --git a/security/security.c b/security/security.c
index 1621a28bf9c4..607e54a0e85f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2174,17 +2174,16 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);

-int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
{
struct security_hook_list *hp;
int rc;

- /*
- * Currently, only one LSM can implement secid_to_secctx (i.e this
- * LSM hook is not "stackable").
- */
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
- rc = hp->hook.secid_to_secctx(secid, secdata, seclen);
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
+ secdata, seclen);
if (rc != LSM_RET_DEFAULT(secid_to_secctx))
return rc;
}
--
2.31.1

2021-07-22 00:59:44

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 09/25] LSM: Use lsmblob in security_ipc_getsecid

There may be more than one LSM that provides IPC data
for auditing. Change security_ipc_getsecid() to fill in
a lsmblob structure instead of the u32 secid. The
audit data structure containing the secid will be updated
later, so there is a bit of scaffolding here.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
---
include/linux/security.h | 7 ++++---
kernel/auditsc.c | 7 ++++++-
security/security.c | 12 +++++++++---
3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index ef33be59998e..886128899d5f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -518,7 +518,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5);
void security_task_to_inode(struct task_struct *p, struct inode *inode);
int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
int security_msg_msg_alloc(struct msg_msg *msg);
void security_msg_msg_free(struct msg_msg *msg);
int security_msg_queue_alloc(struct kern_ipc_perm *msq);
@@ -1275,9 +1275,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
return 0;
}

-static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}

static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index df8a57c5355d..b4d214b21b97 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2337,12 +2337,17 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
{
struct audit_context *context = audit_context();
+ struct lsmblob blob;

context->ipc.uid = ipcp->uid;
context->ipc.gid = ipcp->gid;
context->ipc.mode = ipcp->mode;
context->ipc.has_perm = 0;
- security_ipc_getsecid(ipcp, &context->ipc.osid);
+ security_ipc_getsecid(ipcp, &blob);
+ /* context->ipc.osid will be changed to a lsmblob later in
+ * the patch series. This will allow auditing of all the object
+ * labels associated with the ipc object. */
+ context->ipc.osid = lsmblob_value(&blob);
context->type = AUDIT_IPC;
}

diff --git a/security/security.c b/security/security.c
index 607e54a0e85f..c38816ef9778 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1994,10 +1994,16 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
return call_int_hook(ipc_permission, 0, ipcp, flag);
}

-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(ipc_getsecid, ipcp, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->lsmid->slot]);
+ }
}

int security_msg_msg_alloc(struct msg_msg *msg)
--
2.31.1

2021-07-22 01:00:30

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 10/25] LSM: Use lsmblob in security_task_getsecid

Change the security_task_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in
a lsmblob structure instead of a u32 secid in support of
LSM stacking. Audit interfaces will need to collect all
possible secids for possible reporting.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
drivers/android/binder.c | 12 +-----
include/linux/security.h | 14 ++++---
kernel/audit.c | 16 +++-----
kernel/auditfilter.c | 4 +-
kernel/auditsc.c | 25 ++++++------
net/netlabel/netlabel_unlabeled.c | 5 ++-
net/netlabel/netlabel_user.h | 6 ++-
security/integrity/ima/ima_appraise.c | 10 +++--
security/integrity/ima/ima_main.c | 56 +++++++++++++++------------
security/security.c | 25 +++++++++---
10 files changed, 94 insertions(+), 79 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 3e97a6de5e80..96dd728809ef 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2710,7 +2710,6 @@ static void binder_transaction(struct binder_proc *proc,
t->priority = task_nice(current);

if (target_node && target_node->txn_security_ctx) {
- u32 secid;
struct lsmblob blob;
size_t added_size;

@@ -2723,16 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
* here; however, it isn't clear that binder would handle that
* case well anyway.
*/
- security_task_getsecid_obj(proc->tsk, &secid);
- /*
- * Later in this patch set security_task_getsecid() will
- * provide a lsmblob instead of a secid. lsmblob_init
- * is used to ensure that all the secids in the lsmblob
- * get the value returned from security_task_getsecid(),
- * which means that the one expected by
- * security_secid_to_secctx() will be set.
- */
- lsmblob_init(&blob, secid);
+ security_task_getsecid_obj(proc->tsk, &blob);
ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
if (ret) {
return_error = BR_FAILED_REPLY;
diff --git a/include/linux/security.h b/include/linux/security.h
index 886128899d5f..4070cef152f7 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -500,8 +500,8 @@ int security_task_fix_setgid(struct cred *new, const struct cred *old,
int security_task_setpgid(struct task_struct *p, pid_t pgid);
int security_task_getpgid(struct task_struct *p);
int security_task_getsid(struct task_struct *p);
-void security_task_getsecid_subj(struct task_struct *p, u32 *secid);
-void security_task_getsecid_obj(struct task_struct *p, u32 *secid);
+void security_task_getsecid_subj(struct task_struct *p, struct lsmblob *blob);
+void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob);
int security_task_setnice(struct task_struct *p, int nice);
int security_task_setioprio(struct task_struct *p, int ioprio);
int security_task_getioprio(struct task_struct *p);
@@ -1197,14 +1197,16 @@ static inline int security_task_getsid(struct task_struct *p)
return 0;
}

-static inline void security_task_getsecid_subj(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid_subj(struct task_struct *p,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}

-static inline void security_task_getsecid_obj(struct task_struct *p, u32 *secid)
+static inline void security_task_getsecid_obj(struct task_struct *p,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}

static inline int security_task_setnice(struct task_struct *p, int nice)
diff --git a/kernel/audit.c b/kernel/audit.c
index 22286163e93e..d92c7b894183 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2139,19 +2139,12 @@ int audit_log_task_context(struct audit_buffer *ab)
char *ctx = NULL;
unsigned len;
int error;
- u32 sid;
struct lsmblob blob;

- security_task_getsecid_subj(current, &sid);
- if (!sid)
+ security_task_getsecid_subj(current, &blob);
+ if (!lsmblob_is_set(&blob))
return 0;

- /*
- * lsmblob_init sets all values in the lsmblob to sid.
- * This is temporary until security_task_getsecid is converted
- * to use a lsmblob, which happens later in this patch set.
- */
- lsmblob_init(&blob, sid);
error = security_secid_to_secctx(&blob, &ctx, &len);
if (error) {
if (error != -EINVAL)
@@ -2359,6 +2352,7 @@ int audit_set_loginuid(kuid_t loginuid)
int audit_signal_info(int sig, struct task_struct *t)
{
kuid_t uid = current_uid(), auid;
+ struct lsmblob blob;

if (auditd_test_task(t) &&
(sig == SIGTERM || sig == SIGHUP ||
@@ -2369,7 +2363,9 @@ int audit_signal_info(int sig, struct task_struct *t)
audit_sig_uid = auid;
else
audit_sig_uid = uid;
- security_task_getsecid_subj(current, &audit_sig_sid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until audit_sig_sid is converted */
+ audit_sig_sid = blob.secid[0];
}

return audit_signal_info_syscall(t);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 6a04d762d272..1ba14a7a38f7 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1330,7 +1330,6 @@ int audit_filter(int msgtype, unsigned int listtype)
for (i = 0; i < e->rule.field_count; i++) {
struct audit_field *f = &e->rule.fields[i];
pid_t pid;
- u32 sid;
struct lsmblob blob;

switch (f->type) {
@@ -1362,8 +1361,7 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_CLR:
if (f->lsm_isset) {
security_task_getsecid_subj(current,
- &sid);
- lsmblob_init(&blob, sid);
+ &blob);
result = security_audit_rule_match(
&blob, f->type, f->op,
f->lsm_rules);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index b4d214b21b97..50e3f2f4cb49 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -477,7 +477,6 @@ static int audit_filter_rules(struct task_struct *tsk,
{
const struct cred *cred;
int i, need_sid = 1;
- u32 sid;
struct lsmblob blob;
unsigned int sessionid;

@@ -674,17 +673,9 @@ static int audit_filter_rules(struct task_struct *tsk,
logged upon error */
if (f->lsm_isset) {
if (need_sid) {
- security_task_getsecid_subj(tsk, &sid);
+ security_task_getsecid_subj(tsk, &blob);
need_sid = 0;
}
- /*
- * lsmblob_init sets all values in the lsmblob
- * to sid. This is temporary until
- * security_task_getsecid() is converted to
- * provide a lsmblob, which happens later in
- * this patch set.
- */
- lsmblob_init(&blob, sid);
result = security_audit_rule_match(&blob,
f->type, f->op,
f->lsm_rules);
@@ -2439,12 +2430,15 @@ int __audit_sockaddr(int len, void *a)
void __audit_ptrace(struct task_struct *t)
{
struct audit_context *context = audit_context();
+ struct lsmblob blob;

context->target_pid = task_tgid_nr(t);
context->target_auid = audit_get_loginuid(t);
context->target_uid = task_uid(t);
context->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &context->target_sid);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding - until target_sid is converted */
+ context->target_sid = blob.secid[0];
memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
}

@@ -2460,6 +2454,7 @@ int audit_signal_info_syscall(struct task_struct *t)
struct audit_aux_data_pids *axp;
struct audit_context *ctx = audit_context();
kuid_t t_uid = task_uid(t);
+ struct lsmblob blob;

if (!audit_signals || audit_dummy_context())
return 0;
@@ -2471,7 +2466,9 @@ int audit_signal_info_syscall(struct task_struct *t)
ctx->target_auid = audit_get_loginuid(t);
ctx->target_uid = t_uid;
ctx->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &ctx->target_sid);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding until target_sid is converted */
+ ctx->target_sid = blob.secid[0];
memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
return 0;
}
@@ -2492,7 +2489,9 @@ int audit_signal_info_syscall(struct task_struct *t)
axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
axp->target_uid[axp->pid_count] = t_uid;
axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &axp->target_sid[axp->pid_count]);
+ security_task_getsecid_obj(t, &blob);
+ /* scaffolding until target_sid is converted */
+ axp->target_sid[axp->pid_count] = blob.secid[0];
memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
axp->pid_count++;

diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 5cbbc469ac7c..098d0a1a3330 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1564,11 +1564,14 @@ int __init netlbl_unlabel_defconf(void)
int ret_val;
struct netlbl_dom_map *entry;
struct netlbl_audit audit_info;
+ struct lsmblob blob;

/* Only the kernel is allowed to call this function and the only time
* it is called is at bootup before the audit subsystem is reporting
* messages so don't worry to much about these values. */
- security_task_getsecid_subj(current, &audit_info.secid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until audit_info.secid is converted */
+ audit_info.secid = blob.secid[0];
audit_info.loginuid = GLOBAL_ROOT_UID;
audit_info.sessionid = 0;

diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 6190cbf94bf0..aa31f7bf79ee 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -32,7 +32,11 @@
*/
static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
{
- security_task_getsecid_subj(current, &audit_info->secid);
+ struct lsmblob blob;
+
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until secid is converted */
+ audit_info->secid = blob.secid[0];
audit_info->loginuid = audit_get_loginuid(current);
audit_info->sessionid = audit_get_sessionid(current);
}
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index ef9dcfce45d4..e3d903d6e5e7 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -71,14 +71,16 @@ bool is_ima_appraise_enabled(void)
int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
int mask, enum ima_hooks func)
{
- u32 secid;
+ struct lsmblob blob;

if (!ima_appraise)
return 0;

- security_task_getsecid_subj(current, &secid);
- return ima_match_policy(mnt_userns, inode, current_cred(), secid, func,
- mask, IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding the .secid[0] */
+ return ima_match_policy(mnt_userns, inode, current_cred(),
+ blob.secid[0], func, mask,
+ IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
}

static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 287b90509006..29befd24b945 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -388,12 +388,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
*/
int ima_file_mmap(struct file *file, unsigned long prot)
{
- u32 secid;
+ struct lsmblob blob;

if (file && (prot & PROT_EXEC)) {
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL,
- 0, MAY_EXEC, MMAP_CHECK);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding - until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0],
+ NULL, 0, MAY_EXEC, MMAP_CHECK);
}

return 0;
@@ -419,9 +420,9 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
char *pathbuf = NULL;
const char *pathname = NULL;
struct inode *inode;
+ struct lsmblob blob;
int result = 0;
int action;
- u32 secid;
int pcr;

/* Is mprotect making an mmap'ed file executable? */
@@ -429,11 +430,12 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
!(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
return 0;

- security_task_getsecid_subj(current, &secid);
+ security_task_getsecid_subj(current, &blob);
inode = file_inode(vma->vm_file);
+ /* scaffolding */
action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
- current_cred(), secid, MAY_EXEC, MMAP_CHECK,
- &pcr, &template, NULL);
+ current_cred(), blob.secid[0], MAY_EXEC,
+ MMAP_CHECK, &pcr, &template, NULL);

/* Is the mmap'ed file in policy? */
if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
@@ -469,10 +471,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
{
int ret;
u32 secid;
+ struct lsmblob blob;

- security_task_getsecid_subj(current, &secid);
- ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
- MAY_EXEC, BPRM_CHECK);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
+ NULL, 0, MAY_EXEC, BPRM_CHECK);
if (ret)
return ret;

@@ -493,10 +497,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
*/
int ima_file_check(struct file *file, int mask)
{
- u32 secid;
+ struct lsmblob blob;

- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL, 0,
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
MAY_APPEND), FILE_CHECK);
}
@@ -672,7 +677,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
bool contents)
{
enum ima_hooks func;
- u32 secid;
+ struct lsmblob blob;

/*
* Do devices using pre-allocated memory run the risk of the
@@ -692,8 +697,9 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,

/* Read entire file for all partial reads. */
func = read_idmap[read_id] ?: FILE_CHECK;
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, NULL,
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding - until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], NULL,
0, MAY_READ, func);
}

@@ -722,7 +728,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id read_id)
{
enum ima_hooks func;
- u32 secid;
+ struct lsmblob blob;

/* permit signed certs */
if (!file && read_id == READING_X509_CERTIFICATE)
@@ -735,9 +741,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
}

func = read_idmap[read_id] ?: FILE_CHECK;
- security_task_getsecid_subj(current, &secid);
- return process_measurement(file, current_cred(), secid, buf, size,
- MAY_READ, func);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding until process_measurement changes */
+ return process_measurement(file, current_cred(), blob.secid[0], buf,
+ size, MAY_READ, func);
}

/**
@@ -859,7 +866,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
int digest_hash_len = hash_digest_size[ima_hash_algo];
int violation = 0;
int action = 0;
- u32 secid;
+ struct lsmblob blob;

if (!ima_policy_flag)
return;
@@ -879,9 +886,10 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
* buffer measurements.
*/
if (func) {
- security_task_getsecid_subj(current, &secid);
+ security_task_getsecid_subj(current, &blob);
+ /* scaffolding */
action = ima_get_action(mnt_userns, inode, current_cred(),
- secid, 0, func, &pcr, &template,
+ blob.secid[0], 0, func, &pcr, &template,
func_data);
if (!(action & IMA_MEASURE))
return;
diff --git a/security/security.c b/security/security.c
index c38816ef9778..458fded340ab 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1904,17 +1904,30 @@ int security_task_getsid(struct task_struct *p)
return call_int_hook(task_getsid, 0, p);
}

-void security_task_getsecid_subj(struct task_struct *p, u32 *secid)
+void security_task_getsecid_subj(struct task_struct *p, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(task_getsecid_subj, p, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.task_getsecid_subj,
+ list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.task_getsecid_subj(p, &blob->secid[hp->lsmid->slot]);
+ }
}
EXPORT_SYMBOL(security_task_getsecid_subj);

-void security_task_getsecid_obj(struct task_struct *p, u32 *secid)
+void security_task_getsecid_obj(struct task_struct *p, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(task_getsecid_obj, p, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.task_getsecid_obj, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.task_getsecid_obj(p, &blob->secid[hp->lsmid->slot]);
+ }
}
EXPORT_SYMBOL(security_task_getsecid_obj);

--
2.31.1

2021-07-22 01:02:39

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 11/25] LSM: Use lsmblob in security_inode_getsecid

Change the security_inode_getsecid() interface to fill in a
lsmblob structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
include/linux/security.h | 7 ++++---
kernel/auditsc.c | 6 +++++-
security/integrity/ima/ima_policy.c | 4 +---
security/security.c | 11 +++++++++--
4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 4070cef152f7..aa19fa4a553f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -454,7 +454,7 @@ int security_inode_getsecurity(struct user_namespace *mnt_userns,
void **buffer, bool alloc);
int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
-void security_inode_getsecid(struct inode *inode, u32 *secid);
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
int security_inode_copy_up(struct dentry *src, struct cred **new);
int security_inode_copy_up_xattr(const char *name);
int security_kernfs_init_security(struct kernfs_node *kn_dir,
@@ -1005,9 +1005,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
return 0;
}

-static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
+static inline void security_inode_getsecid(struct inode *inode,
+ struct lsmblob *blob)
{
- *secid = 0;
+ lsmblob_init(blob, 0);
}

static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 50e3f2f4cb49..dcd1b988a2d3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1975,13 +1975,17 @@ static void audit_copy_inode(struct audit_names *name,
const struct dentry *dentry,
struct inode *inode, unsigned int flags)
{
+ struct lsmblob blob;
+
name->ino = inode->i_ino;
name->dev = inode->i_sb->s_dev;
name->mode = inode->i_mode;
name->uid = inode->i_uid;
name->gid = inode->i_gid;
name->rdev = inode->i_rdev;
- security_inode_getsecid(inode, &name->osid);
+ security_inode_getsecid(inode, &blob);
+ /* scaffolding until osid is updated */
+ name->osid = blob.secid[0];
if (flags & AUDIT_INODE_NOEVAL) {
name->fcap_ver = -1;
return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index af612a42eebe..6d112ec89c1b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -608,7 +608,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
return false;
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
- u32 osid;
struct lsmblob lsmdata;

if (!ima_lsm_isset(rule, i)) {
@@ -621,8 +620,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
case LSM_OBJ_USER:
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
- security_inode_getsecid(inode, &osid);
- lsmblob_init(&lsmdata, osid);
+ security_inode_getsecid(inode, &lsmdata);
rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
diff --git a/security/security.c b/security/security.c
index 458fded340ab..da85932a4d53 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1548,9 +1548,16 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
}
EXPORT_SYMBOL(security_inode_listsecurity);

-void security_inode_getsecid(struct inode *inode, u32 *secid)
+void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
{
- call_void_hook(inode_getsecid, inode, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]);
+ }
}

int security_inode_copy_up(struct dentry *src, struct cred **new)
--
2.31.1

2021-07-22 01:04:02

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 12/25] LSM: Use lsmblob in security_cred_getsecid

Change the security_cred_getsecid() interface to fill in a
lsmblob instead of a u32 secid. The associated data elements
in the audit sub-system are changed from a secid to a lsmblob
to accommodate multiple possible LSM audit users.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
include/linux/security.h | 2 +-
kernel/audit.c | 25 +++++++----------------
kernel/audit.h | 3 ++-
kernel/auditsc.c | 33 +++++++++++--------------------
security/integrity/ima/ima_main.c | 8 ++++----
security/security.c | 12 ++++++++---
6 files changed, 35 insertions(+), 48 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index aa19fa4a553f..cdd8d9122795 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -481,7 +481,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
void security_cred_free(struct cred *cred);
int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
void security_transfer_creds(struct cred *new, const struct cred *old);
-void security_cred_getsecid(const struct cred *c, u32 *secid);
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(char *kmod_name);
diff --git a/kernel/audit.c b/kernel/audit.c
index d92c7b894183..8ec64e6e8bc0 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -125,7 +125,7 @@ static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
/* The identity of the user shutting down the audit system. */
static kuid_t audit_sig_uid = INVALID_UID;
static pid_t audit_sig_pid = -1;
-static u32 audit_sig_sid;
+struct lsmblob audit_sig_lsm;

/* Records can be lost in several ways:
0) [suppressed in audit_alloc]
@@ -1441,29 +1441,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
}
case AUDIT_SIGNAL_INFO:
len = 0;
- if (audit_sig_sid) {
- struct lsmblob blob;
-
- /*
- * lsmblob_init sets all values in the lsmblob
- * to audit_sig_sid. This is temporary until
- * audit_sig_sid is converted to a lsmblob, which
- * happens later in this patch set.
- */
- lsmblob_init(&blob, audit_sig_sid);
- err = security_secid_to_secctx(&blob, &ctx, &len);
+ if (lsmblob_is_set(&audit_sig_lsm)) {
+ err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
+ &len);
if (err)
return err;
}
sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
if (!sig_data) {
- if (audit_sig_sid)
+ if (lsmblob_is_set(&audit_sig_lsm))
security_release_secctx(ctx, len);
return -ENOMEM;
}
sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
sig_data->pid = audit_sig_pid;
- if (audit_sig_sid) {
+ if (lsmblob_is_set(&audit_sig_lsm)) {
memcpy(sig_data->ctx, ctx, len);
security_release_secctx(ctx, len);
}
@@ -2352,7 +2344,6 @@ int audit_set_loginuid(kuid_t loginuid)
int audit_signal_info(int sig, struct task_struct *t)
{
kuid_t uid = current_uid(), auid;
- struct lsmblob blob;

if (auditd_test_task(t) &&
(sig == SIGTERM || sig == SIGHUP ||
@@ -2363,9 +2354,7 @@ int audit_signal_info(int sig, struct task_struct *t)
audit_sig_uid = auid;
else
audit_sig_uid = uid;
- security_task_getsecid_subj(current, &blob);
- /* scaffolding until audit_sig_sid is converted */
- audit_sig_sid = blob.secid[0];
+ security_task_getsecid_subj(current, &audit_sig_lsm);
}

return audit_signal_info_syscall(t);
diff --git a/kernel/audit.h b/kernel/audit.h
index b565ea16c0a5..b679517a3030 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -9,6 +9,7 @@
#include <linux/fs.h>
#include <linux/audit.h>
#include <linux/skbuff.h>
+#include <linux/security.h>
#include <uapi/linux/mqueue.h>
#include <linux/tty.h>

@@ -134,7 +135,7 @@ struct audit_context {
kuid_t target_auid;
kuid_t target_uid;
unsigned int target_sessionid;
- u32 target_sid;
+ struct lsmblob target_lsm;
char target_comm[TASK_COMM_LEN];

struct audit_tree_refs *trees, *first_trees;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index dcd1b988a2d3..b5807b9b8a4d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -111,7 +111,7 @@ struct audit_aux_data_pids {
kuid_t target_auid[AUDIT_AUX_PIDS];
kuid_t target_uid[AUDIT_AUX_PIDS];
unsigned int target_sessionid[AUDIT_AUX_PIDS];
- u32 target_sid[AUDIT_AUX_PIDS];
+ struct lsmblob target_lsm[AUDIT_AUX_PIDS];
char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
int pid_count;
};
@@ -997,14 +997,14 @@ static inline void audit_free_context(struct audit_context *context)
}

static int audit_log_pid_context(struct audit_context *context, pid_t pid,
- kuid_t auid, kuid_t uid, unsigned int sessionid,
- u32 sid, char *comm)
+ kuid_t auid, kuid_t uid,
+ unsigned int sessionid,
+ struct lsmblob *blob, char *comm)
{
struct audit_buffer *ab;
char *ctx = NULL;
u32 len;
int rc = 0;
- struct lsmblob blob;

ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
if (!ab)
@@ -1013,9 +1013,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
- if (sid) {
- lsmblob_init(&blob, sid);
- if (security_secid_to_secctx(&blob, &ctx, &len)) {
+ if (lsmblob_is_set(blob)) {
+ if (security_secid_to_secctx(blob, &ctx, &len)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1590,7 +1589,7 @@ static void audit_log_exit(void)
axs->target_auid[i],
axs->target_uid[i],
axs->target_sessionid[i],
- axs->target_sid[i],
+ &axs->target_lsm[i],
axs->target_comm[i]))
call_panic = 1;
}
@@ -1599,7 +1598,7 @@ static void audit_log_exit(void)
audit_log_pid_context(context, context->target_pid,
context->target_auid, context->target_uid,
context->target_sessionid,
- context->target_sid, context->target_comm))
+ &context->target_lsm, context->target_comm))
call_panic = 1;

if (context->pwd.dentry && context->pwd.mnt) {
@@ -1775,7 +1774,7 @@ void __audit_syscall_exit(int success, long return_code)
context->aux = NULL;
context->aux_pids = NULL;
context->target_pid = 0;
- context->target_sid = 0;
+ lsmblob_init(&context->target_lsm, 0);
context->sockaddr_len = 0;
context->type = 0;
context->fds[0] = -1;
@@ -2434,15 +2433,12 @@ int __audit_sockaddr(int len, void *a)
void __audit_ptrace(struct task_struct *t)
{
struct audit_context *context = audit_context();
- struct lsmblob blob;

context->target_pid = task_tgid_nr(t);
context->target_auid = audit_get_loginuid(t);
context->target_uid = task_uid(t);
context->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &blob);
- /* scaffolding - until target_sid is converted */
- context->target_sid = blob.secid[0];
+ security_task_getsecid_obj(t, &context->target_lsm);
memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
}

@@ -2458,7 +2454,6 @@ int audit_signal_info_syscall(struct task_struct *t)
struct audit_aux_data_pids *axp;
struct audit_context *ctx = audit_context();
kuid_t t_uid = task_uid(t);
- struct lsmblob blob;

if (!audit_signals || audit_dummy_context())
return 0;
@@ -2470,9 +2465,7 @@ int audit_signal_info_syscall(struct task_struct *t)
ctx->target_auid = audit_get_loginuid(t);
ctx->target_uid = t_uid;
ctx->target_sessionid = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &blob);
- /* scaffolding until target_sid is converted */
- ctx->target_sid = blob.secid[0];
+ security_task_getsecid_obj(t, &ctx->target_lsm);
memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
return 0;
}
@@ -2493,9 +2486,7 @@ int audit_signal_info_syscall(struct task_struct *t)
axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
axp->target_uid[axp->pid_count] = t_uid;
axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
- security_task_getsecid_obj(t, &blob);
- /* scaffolding until target_sid is converted */
- axp->target_sid[axp->pid_count] = blob.secid[0];
+ security_task_getsecid_obj(t, &axp->target_lsm[axp->pid_count]);
memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
axp->pid_count++;

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 29befd24b945..de084954d0b9 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -470,7 +470,6 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
int ima_bprm_check(struct linux_binprm *bprm)
{
int ret;
- u32 secid;
struct lsmblob blob;

security_task_getsecid_subj(current, &blob);
@@ -480,9 +479,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
if (ret)
return ret;

- security_cred_getsecid(bprm->cred, &secid);
- return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
- MAY_EXEC, CREDS_CHECK);
+ security_cred_getsecid(bprm->cred, &blob);
+ /* scaffolding until process_measurement changes */
+ return process_measurement(bprm->file, bprm->cred, blob.secid[0],
+ NULL, 0, MAY_EXEC, CREDS_CHECK);
}

/**
diff --git a/security/security.c b/security/security.c
index da85932a4d53..b4a268c1aaec 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1798,10 +1798,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
call_void_hook(cred_transfer, new, old);
}

-void security_cred_getsecid(const struct cred *c, u32 *secid)
+void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
{
- *secid = 0;
- call_void_hook(cred_getsecid, c, secid);
+ struct security_hook_list *hp;
+
+ lsmblob_init(blob, 0);
+ hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) {
+ if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
+ continue;
+ hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
+ }
}
EXPORT_SYMBOL(security_cred_getsecid);

--
2.31.1

2021-07-22 01:04:35

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 13/25] IMA: Change internal interfaces to use lsmblobs

The IMA interfaces ima_get_action() and ima_match_policy()
call LSM functions that use lsmblobs. Change the IMA functions
to pass the lsmblob to be compatible with the LSM functions.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
To: Mimi Zohar <[email protected]>
---
security/integrity/ima/ima.h | 6 ++---
security/integrity/ima/ima_api.c | 6 ++---
security/integrity/ima/ima_appraise.c | 5 ++--
security/integrity/ima/ima_main.c | 36 +++++++++++----------------
security/integrity/ima/ima_policy.c | 17 ++++++-------
5 files changed, 31 insertions(+), 39 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 55f3bd4f0b01..a6b59fcaf62a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -251,7 +251,7 @@ static inline void ima_process_queued_keys(void) {}

/* LIM API function definitions */
int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, int mask,
+ const struct cred *cred, struct lsmblob *blob, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data);
@@ -282,8 +282,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);

/* IMA policy related functions */
int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, enum ima_hooks func,
- int mask, int flags, int *pcr,
+ const struct cred *cred, struct lsmblob *blob,
+ enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data);
void ima_init_policy(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index d8e321cc6936..691f68d478f1 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -165,7 +165,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: pointer to the inode associated with the object being validated
* @cred: pointer to credentials structure to validate
- * @secid: secid of the task being validated
+ * @blob: LSM data of the task being validated
* @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
* MAY_APPEND)
* @func: caller identifier
@@ -185,7 +185,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
*
*/
int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, int mask,
+ const struct cred *cred, struct lsmblob *blob, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data)
@@ -194,7 +194,7 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,

flags &= ima_policy_flag;

- return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
+ return ima_match_policy(mnt_userns, inode, cred, blob, func, mask,
flags, pcr, template_desc, func_data);
}

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index e3d903d6e5e7..de50ed4df878 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -77,10 +77,9 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
return 0;

security_task_getsecid_subj(current, &blob);
- /* scaffolding the .secid[0] */
return ima_match_policy(mnt_userns, inode, current_cred(),
- blob.secid[0], func, mask,
- IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+ &blob, func, mask, IMA_APPRAISE | IMA_HASH,
+ NULL, NULL, NULL);
}

static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index de084954d0b9..2bcbfb577860 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -194,8 +194,8 @@ void ima_file_free(struct file *file)
}

static int process_measurement(struct file *file, const struct cred *cred,
- u32 secid, char *buf, loff_t size, int mask,
- enum ima_hooks func)
+ struct lsmblob *blob, char *buf, loff_t size,
+ int mask, enum ima_hooks func)
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
@@ -218,7 +218,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
* bitmask based on the appraise/audit/measurement policy.
* Included is the appraise submask.
*/
- action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid,
+ action = ima_get_action(file_mnt_user_ns(file), inode, cred, blob,
mask, func, &pcr, &template_desc, NULL);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
@@ -392,8 +392,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)

if (file && (prot & PROT_EXEC)) {
security_task_getsecid_subj(current, &blob);
- /* scaffolding - until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0],
+ return process_measurement(file, current_cred(), &blob,
NULL, 0, MAY_EXEC, MMAP_CHECK);
}

@@ -434,7 +433,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
inode = file_inode(vma->vm_file);
/* scaffolding */
action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
- current_cred(), blob.secid[0], MAY_EXEC,
+ current_cred(), &blob, MAY_EXEC,
MMAP_CHECK, &pcr, &template, NULL);

/* Is the mmap'ed file in policy? */
@@ -473,16 +472,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
struct lsmblob blob;

security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
- NULL, 0, MAY_EXEC, BPRM_CHECK);
+ ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
+ MAY_EXEC, BPRM_CHECK);
if (ret)
return ret;

security_cred_getsecid(bprm->cred, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(bprm->file, bprm->cred, blob.secid[0],
- NULL, 0, MAY_EXEC, CREDS_CHECK);
+ return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
+ MAY_EXEC, CREDS_CHECK);
}

/**
@@ -500,8 +497,7 @@ int ima_file_check(struct file *file, int mask)
struct lsmblob blob;

security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
+ return process_measurement(file, current_cred(), &blob, NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
MAY_APPEND), FILE_CHECK);
}
@@ -698,9 +694,8 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
/* Read entire file for all partial reads. */
func = read_idmap[read_id] ?: FILE_CHECK;
security_task_getsecid_subj(current, &blob);
- /* scaffolding - until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], NULL,
- 0, MAY_READ, func);
+ return process_measurement(file, current_cred(), &blob, NULL, 0,
+ MAY_READ, func);
}

const int read_idmap[READING_MAX_ID] = {
@@ -742,9 +737,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,

func = read_idmap[read_id] ?: FILE_CHECK;
security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], buf,
- size, MAY_READ, func);
+ return process_measurement(file, current_cred(), &blob, buf, size,
+ MAY_READ, func);
}

/**
@@ -889,7 +883,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
security_task_getsecid_subj(current, &blob);
/* scaffolding */
action = ima_get_action(mnt_userns, inode, current_cred(),
- blob.secid[0], 0, func, &pcr, &template,
+ &blob, 0, func, &pcr, &template,
func_data);
if (!(action & IMA_MEASURE))
return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 6d112ec89c1b..a2b8c0ad8b74 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -548,7 +548,7 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: a pointer to an inode
* @cred: a pointer to a credentials structure for user validation
- * @secid: the secid of the task to be validated
+ * @blob: the lsm data of the task to be validated
* @func: LIM hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @func_data: func specific data, may be NULL
@@ -558,8 +558,8 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
static bool ima_match_rules(struct ima_rule_entry *rule,
struct user_namespace *mnt_userns,
struct inode *inode, const struct cred *cred,
- u32 secid, enum ima_hooks func, int mask,
- const char *func_data)
+ struct lsmblob *blob, enum ima_hooks func,
+ int mask, const char *func_data)
{
int i;

@@ -628,8 +628,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- lsmblob_init(&lsmdata, secid);
- rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
+ rc = ima_filter_rule_match(blob, rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
break;
@@ -673,7 +672,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @inode: pointer to an inode for which the policy decision is being made
* @cred: pointer to a credentials structure for which the policy decision is
* being made
- * @secid: LSM secid of the task to be validated
+ * @blob: LSM data of the task to be validated
* @func: IMA hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @pcr: set the pcr to extend
@@ -688,8 +687,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* than writes so ima_match_policy() is classical RCU candidate.
*/
int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, enum ima_hooks func,
- int mask, int flags, int *pcr,
+ const struct cred *cred, struct lsmblob *blob,
+ enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data)
{
@@ -705,7 +704,7 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
if (!(entry->action & actmask))
continue;

- if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
+ if (!ima_match_rules(entry, mnt_userns, inode, cred, blob,
func, mask, func_data))
continue;

--
2.31.1

2021-07-22 01:05:06

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 14/25] LSM: Specify which LSM to display

Create a new entry "interface_lsm" in the procfs attr directory for
controlling which LSM security information is displayed for a
process. A process can only read or write its own display value.

The name of an active LSM that supplies hooks for
human readable data may be written to "interface_lsm" to set the
value. The name of the LSM currently in use can be read from
"interface_lsm". At this point there can only be one LSM capable
of display active. A helper function lsm_task_ilsm() is
provided to get the interface lsm slot for a task_struct.

Setting the "interface_lsm" requires that all security modules using
setprocattr hooks allow the action. Each security module is
responsible for defining its policy.

AppArmor hook provided by John Johansen <[email protected]>
SELinux hook provided by Stephen Smalley <[email protected]>

Signed-off-by: Casey Schaufler <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Stephen Smalley <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: John Johansen <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
.../ABI/testing/procfs-attr-lsm_display | 22 +++
Documentation/security/lsm.rst | 14 ++
fs/proc/base.c | 1 +
include/linux/lsm_hooks.h | 17 ++
security/apparmor/include/apparmor.h | 3 +-
security/apparmor/lsm.c | 32 ++++
security/security.c | 166 ++++++++++++++++--
security/selinux/hooks.c | 11 ++
security/selinux/include/classmap.h | 2 +-
security/smack/smack_lsm.c | 7 +
10 files changed, 256 insertions(+), 19 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display

diff --git a/Documentation/ABI/testing/procfs-attr-lsm_display b/Documentation/ABI/testing/procfs-attr-lsm_display
new file mode 100644
index 000000000000..0f60005c235c
--- /dev/null
+++ b/Documentation/ABI/testing/procfs-attr-lsm_display
@@ -0,0 +1,22 @@
+What: /proc/*/attr/lsm_display
+Contact: [email protected],
+Description: The name of the Linux security module (LSM) that will
+ provide information in the /proc/*/attr/current,
+ /proc/*/attr/prev and /proc/*/attr/exec interfaces.
+ The details of permissions required to read from
+ this interface are dependent on the LSMs active on the
+ system.
+ A process cannot write to this interface unless it
+ refers to itself.
+ The other details of permissions required to write to
+ this interface are dependent on the LSMs active on the
+ system.
+ The format of the data used by this interface is a
+ text string identifying the name of an LSM. The values
+ accepted are:
+ selinux - the SELinux LSM
+ smack - the Smack LSM
+ apparmor - The AppArmor LSM
+ By convention the LSM names are lower case and do not
+ contain special characters.
+Users: LSM user-space
diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index 6a2a2e973080..b77b4a540391 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -129,3 +129,17 @@ to identify it as the first security module to be registered.
The capabilities security module does not use the general security
blobs, unlike other modules. The reasons are historical and are
based on overhead, complexity and performance concerns.
+
+LSM External Interfaces
+=======================
+
+The LSM infrastructure does not generally provide external interfaces.
+The individual security modules provide what external interfaces they
+require.
+
+The file ``/sys/kernel/security/lsm`` provides a comma
+separated list of the active security modules.
+
+The file ``/proc/pid/attr/interface_lsm`` contains the name of the security
+module for which the ``/proc/pid/attr/current`` interface will
+apply. This interface can be written to.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index e5b5f7709d48..f80ed1c40053 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2820,6 +2820,7 @@ static const struct pid_entry attr_dir_stuff[] = {
ATTR(NULL, "fscreate", 0666),
ATTR(NULL, "keycreate", 0666),
ATTR(NULL, "sockcreate", 0666),
+ ATTR(NULL, "interface_lsm", 0666),
#ifdef CONFIG_SECURITY_SMACK
DIR("smack", 0555,
proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c61a16f0a5bc..d2c4bc94d47f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1686,4 +1686,21 @@ static inline void security_delete_hooks(struct security_hook_list *hooks,

extern int lsm_inode_alloc(struct inode *inode);

+/**
+ * lsm_task_ilsm - the "interface_lsm" for this task
+ * @task: The task to report on
+ *
+ * Returns the task's interface LSM slot.
+ */
+static inline int lsm_task_ilsm(struct task_struct *task)
+{
+#ifdef CONFIG_SECURITY
+ int *ilsm = task->security;
+
+ if (ilsm)
+ return *ilsm;
+#endif
+ return LSMBLOB_INVALID;
+}
+
#endif /* ! __LINUX_LSM_HOOKS_H */
diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 1fbabdb565a8..b1622fcb4394 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -28,8 +28,9 @@
#define AA_CLASS_SIGNAL 10
#define AA_CLASS_NET 14
#define AA_CLASS_LABEL 16
+#define AA_CLASS_DISPLAY_LSM 17

-#define AA_CLASS_LAST AA_CLASS_LABEL
+#define AA_CLASS_LAST AA_CLASS_DISPLAY_LSM

/* Control parameters settable through module/boot flags */
extern enum audit_mode aa_g_audit;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 392e25940d1f..4237536106aa 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -621,6 +621,25 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
return error;
}

+
+static int profile_interface_lsm(struct aa_profile *profile,
+ struct common_audit_data *sa)
+{
+ struct aa_perms perms = { };
+ unsigned int state;
+
+ state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM);
+ if (state) {
+ aa_compute_perms(profile->policy.dfa, state, &perms);
+ aa_apply_modes_to_perms(profile, &perms);
+ aad(sa)->label = &profile->label;
+
+ return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL);
+ }
+
+ return 0;
+}
+
static int apparmor_setprocattr(const char *name, void *value,
size_t size)
{
@@ -632,6 +651,19 @@ static int apparmor_setprocattr(const char *name, void *value,
if (size == 0)
return -EINVAL;

+ /* LSM infrastructure does actual setting of interface_lsm if allowed */
+ if (!strcmp(name, "interface_lsm")) {
+ struct aa_profile *profile;
+ struct aa_label *label;
+
+ aad(&sa)->info = "set interface lsm";
+ label = begin_current_label_crit_section();
+ error = fn_for_each_confined(label, profile,
+ profile_interface_lsm(profile, &sa));
+ end_current_label_crit_section(label);
+ return error;
+ }
+
/* AppArmor requires that the buffer must be null terminated atm */
if (args[size - 1] != '\0') {
/* null terminate */
diff --git a/security/security.c b/security/security.c
index b4a268c1aaec..7829b8f5d15f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -77,7 +77,16 @@ static struct kmem_cache *lsm_file_cache;
static struct kmem_cache *lsm_inode_cache;

char *lsm_names;
-static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
+
+/*
+ * The task blob includes the "interface_lsm" slot used for
+ * chosing which module presents contexts.
+ * Using a long to avoid potential alignment issues with
+ * module assigned task blobs.
+ */
+static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
+ .lbs_task = sizeof(long),
+};

/* Boot-time LSM user choice */
static __initdata const char *chosen_lsm_order;
@@ -671,6 +680,8 @@ int lsm_inode_alloc(struct inode *inode)
*/
static int lsm_task_alloc(struct task_struct *task)
{
+ int *ilsm;
+
if (blob_sizes.lbs_task == 0) {
task->security = NULL;
return 0;
@@ -679,6 +690,15 @@ static int lsm_task_alloc(struct task_struct *task)
task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
if (task->security == NULL)
return -ENOMEM;
+
+ /*
+ * The start of the task blob contains the "interface" LSM slot number.
+ * Start with it set to the invalid slot number, indicating that the
+ * default first registered LSM be displayed.
+ */
+ ilsm = task->security;
+ *ilsm = LSMBLOB_INVALID;
+
return 0;
}

@@ -1734,14 +1754,26 @@ int security_file_open(struct file *file)

int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
{
+ int *oilsm = current->security;
+ int *nilsm;
int rc = lsm_task_alloc(task);

- if (rc)
+ if (unlikely(rc))
return rc;
+
rc = call_int_hook(task_alloc, 0, task, clone_flags);
- if (unlikely(rc))
+ if (unlikely(rc)) {
security_task_free(task);
- return rc;
+ return rc;
+ }
+
+ if (oilsm) {
+ nilsm = task->security;
+ if (nilsm)
+ *nilsm = *oilsm;
+ }
+
+ return 0;
}

void security_task_free(struct task_struct *task)
@@ -2173,23 +2205,110 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
char **value)
{
struct security_hook_list *hp;
+ int ilsm = lsm_task_ilsm(current);
+ int slot = 0;
+
+ if (!strcmp(name, "interface_lsm")) {
+ /*
+ * lsm_slot will be 0 if there are no displaying modules.
+ */
+ if (lsm_slot == 0)
+ return -EINVAL;
+
+ /*
+ * Only allow getting the current process' interface_lsm.
+ * There are too few reasons to get another process'
+ * interface_lsm and too many LSM policy issues.
+ */
+ if (current != p)
+ return -EINVAL;
+
+ ilsm = lsm_task_ilsm(p);
+ if (ilsm != LSMBLOB_INVALID)
+ slot = ilsm;
+ *value = kstrdup(lsm_slotlist[slot]->lsm, GFP_KERNEL);
+ if (*value)
+ return strlen(*value);
+ return -ENOMEM;
+ }

hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
continue;
+ if (lsm == NULL && ilsm != LSMBLOB_INVALID &&
+ ilsm != hp->lsmid->slot)
+ continue;
return hp->hook.getprocattr(p, name, value);
}
return LSM_RET_DEFAULT(getprocattr);
}

+/**
+ * security_setprocattr - Set process attributes via /proc
+ * @lsm: name of module involved, or NULL
+ * @name: name of the attribute
+ * @value: value to set the attribute to
+ * @size: size of the value
+ *
+ * Set the process attribute for the specified security module
+ * to the specified value. Note that this can only be used to set
+ * the process attributes for the current, or "self" process.
+ * The /proc code has already done this check.
+ *
+ * Returns 0 on success, an appropriate code otherwise.
+ */
int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size)
{
struct security_hook_list *hp;
+ char *termed;
+ char *copy;
+ int *ilsm = current->security;
+ int rc = -EINVAL;
+ int slot = 0;
+
+ if (!strcmp(name, "interface_lsm")) {
+ /*
+ * Change the "interface_lsm" value only if all the security
+ * modules that support setting a procattr allow it.
+ * It is assumed that all such security modules will be
+ * cooperative.
+ */
+ if (size == 0)
+ return -EINVAL;
+
+ hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
+ list) {
+ rc = hp->hook.setprocattr(name, value, size);
+ if (rc < 0)
+ return rc;
+ }
+
+ rc = -EINVAL;
+
+ copy = kmemdup_nul(value, size, GFP_KERNEL);
+ if (copy == NULL)
+ return -ENOMEM;
+
+ termed = strsep(&copy, " \n");
+
+ for (slot = 0; slot < lsm_slot; slot++)
+ if (!strcmp(termed, lsm_slotlist[slot]->lsm)) {
+ *ilsm = lsm_slotlist[slot]->slot;
+ rc = size;
+ break;
+ }
+
+ kfree(termed);
+ return rc;
+ }

hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
continue;
+ if (lsm == NULL && *ilsm != LSMBLOB_INVALID &&
+ *ilsm != hp->lsmid->slot)
+ continue;
return hp->hook.setprocattr(name, value, size);
}
return LSM_RET_DEFAULT(setprocattr);
@@ -2209,15 +2328,15 @@ EXPORT_SYMBOL(security_ismaclabel);
int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
{
struct security_hook_list *hp;
- int rc;
+ int ilsm = lsm_task_ilsm(current);

hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
- secdata, seclen);
- if (rc != LSM_RET_DEFAULT(secid_to_secctx))
- return rc;
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+ return hp->hook.secid_to_secctx(
+ blob->secid[hp->lsmid->slot],
+ secdata, seclen);
}

return LSM_RET_DEFAULT(secid_to_secctx);
@@ -2228,16 +2347,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob)
{
struct security_hook_list *hp;
- int rc;
+ int ilsm = lsm_task_ilsm(current);

lsmblob_init(blob, 0);
hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- rc = hp->hook.secctx_to_secid(secdata, seclen,
- &blob->secid[hp->lsmid->slot]);
- if (rc != 0)
- return rc;
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+ return hp->hook.secctx_to_secid(secdata, seclen,
+ &blob->secid[hp->lsmid->slot]);
}
return 0;
}
@@ -2245,7 +2363,14 @@ EXPORT_SYMBOL(security_secctx_to_secid);

void security_release_secctx(char *secdata, u32 seclen)
{
- call_void_hook(release_secctx, secdata, seclen);
+ struct security_hook_list *hp;
+ int ilsm = lsm_task_ilsm(current);
+
+ hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
+ hp->hook.release_secctx(secdata, seclen);
+ return;
+ }
}
EXPORT_SYMBOL(security_release_secctx);

@@ -2386,8 +2511,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
int __user *optlen, unsigned len)
{
- return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
- optval, optlen, len);
+ int ilsm = lsm_task_ilsm(current);
+ struct security_hook_list *hp;
+
+ hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
+ list)
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+ return hp->hook.socket_getpeersec_stream(sock, optval,
+ optlen, len);
+ return -ENOPROTOOPT;
}

int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index f84b6c274a10..3b95eb39a3bf 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6500,6 +6500,17 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
/*
* Basic control over ability to set these attributes at all.
*/
+
+ /*
+ * For setting interface_lsm, we only perform a permission check;
+ * the actual update to the interface_lsm value is handled by the
+ * LSM framework.
+ */
+ if (!strcmp(name, "interface_lsm"))
+ return avc_has_perm(&selinux_state,
+ mysid, mysid, SECCLASS_PROCESS2,
+ PROCESS2__SETDISPLAY, NULL);
+
if (!strcmp(name, "exec"))
error = avc_has_perm(&selinux_state,
mysid, mysid, SECCLASS_PROCESS,
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 62d19bccf3de..8f4b0dd6dd78 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -53,7 +53,7 @@ struct security_class_mapping secclass_map[] = {
"execmem", "execstack", "execheap", "setkeycreate",
"setsockcreate", "getrlimit", NULL } },
{ "process2",
- { "nnp_transition", "nosuid_transition", NULL } },
+ { "nnp_transition", "nosuid_transition", "setdisplay", NULL } },
{ "system",
{ "ipc_info", "syslog_read", "syslog_mod",
"syslog_console", "module_request", "module_load", NULL } },
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5c10ad27be37..7aa7ea38f627 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3508,6 +3508,13 @@ static int smack_setprocattr(const char *name, void *value, size_t size)
struct smack_known_list_elem *sklep;
int rc;

+ /*
+ * Allow the /proc/.../attr/current and SO_PEERSEC "interface_lsm"
+ * to be reset at will.
+ */
+ if (strcmp(name, "interface_lsm") == 0)
+ return 0;
+
if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
return -EPERM;

--
2.31.1

2021-07-22 01:07:03

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 16/25] LSM: Use lsmcontext in security_secid_to_secctx

Replace the (secctx,seclen) pointer pair with a single
lsmcontext pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.

Reviewed-by: Kees Cook <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
drivers/android/binder.c | 26 +++++++---------
include/linux/security.h | 4 +--
include/net/scm.h | 9 ++----
kernel/audit.c | 39 +++++++++++-------------
kernel/auditsc.c | 31 +++++++------------
net/ipv4/ip_sockglue.c | 8 ++---
net/netfilter/nf_conntrack_netlink.c | 18 +++++------
net/netfilter/nf_conntrack_standalone.c | 7 ++---
net/netfilter/nfnetlink_queue.c | 5 +++-
net/netlabel/netlabel_unlabeled.c | 40 ++++++++-----------------
net/netlabel/netlabel_user.c | 7 ++---
security/security.c | 10 +++++--
12 files changed, 81 insertions(+), 123 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 8976ac6a5adb..2c3a2348a144 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2459,9 +2459,7 @@ static void binder_transaction(struct binder_proc *proc,
binder_size_t last_fixup_min_off = 0;
struct binder_context *context = proc->context;
int t_debug_id = atomic_inc_return(&binder_last_id);
- char *secctx = NULL;
- u32 secctx_sz = 0;
- struct lsmcontext scaff; /* scaffolding */
+ struct lsmcontext lsmctx = { };

e = binder_transaction_log_add(&binder_transaction_log);
e->debug_id = t_debug_id;
@@ -2724,14 +2722,14 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &blob);
- ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
+ ret = security_secid_to_secctx(&blob, &lsmctx);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
return_error_line = __LINE__;
goto err_get_secctx_failed;
}
- added_size = ALIGN(secctx_sz, sizeof(u64));
+ added_size = ALIGN(lsmctx.len, sizeof(u64));
extra_buffers_size += added_size;
if (extra_buffers_size < added_size) {
/* integer overflow of extra_buffers_size */
@@ -2758,24 +2756,22 @@ static void binder_transaction(struct binder_proc *proc,
t->buffer = NULL;
goto err_binder_alloc_buf_failed;
}
- if (secctx) {
+ if (lsmctx.context) {
int err;
size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
ALIGN(tr->offsets_size, sizeof(void *)) +
ALIGN(extra_buffers_size, sizeof(void *)) -
- ALIGN(secctx_sz, sizeof(u64));
+ ALIGN(lsmctx.len, sizeof(u64));

t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
err = binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
- secctx, secctx_sz);
+ lsmctx.context, lsmctx.len);
if (err) {
t->security_ctx = 0;
WARN_ON(1);
}
- lsmcontext_init(&scaff, secctx, secctx_sz, 0);
- security_release_secctx(&scaff);
- secctx = NULL;
+ security_release_secctx(&lsmctx);
}
t->buffer->debug_id = t->debug_id;
t->buffer->transaction = t;
@@ -2832,7 +2828,7 @@ static void binder_transaction(struct binder_proc *proc,
off_end_offset = off_start_offset + tr->offsets_size;
sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
- ALIGN(secctx_sz, sizeof(u64));
+ ALIGN(lsmctx.len, sizeof(u64));
off_min = 0;
for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
buffer_offset += sizeof(binder_size_t)) {
@@ -3116,10 +3112,8 @@ static void binder_transaction(struct binder_proc *proc,
binder_alloc_free_buf(&target_proc->alloc, t->buffer);
err_binder_alloc_buf_failed:
err_bad_extra_size:
- if (secctx) {
- lsmcontext_init(&scaff, secctx, secctx_sz, 0);
- security_release_secctx(&scaff);
- }
+ if (lsmctx.context)
+ security_release_secctx(&lsmctx);
err_get_secctx_failed:
kfree(tcomplete);
binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
diff --git a/include/linux/security.h b/include/linux/security.h
index 041e87f3fe4e..b19bd9e1d583 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -578,7 +578,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1433,7 @@ static inline int security_ismaclabel(const char *name)
}

static inline int security_secid_to_secctx(struct lsmblob *blob,
- char **secdata, u32 *seclen)
+ struct lsmcontext *cp)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/scm.h b/include/net/scm.h
index f273c4d777ec..b77a52f93389 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -94,8 +94,6 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
{
struct lsmcontext context;
struct lsmblob lb;
- char *secdata;
- u32 seclen;
int err;

if (test_bit(SOCK_PASSSEC, &sock->flags)) {
@@ -103,12 +101,11 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
* and the infrastructure will know which it is.
*/
lsmblob_init(&lb, scm->secid);
- err = security_secid_to_secctx(&lb, &secdata, &seclen);
+ err = security_secid_to_secctx(&lb, &context);

if (!err) {
- put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
- /*scaffolding*/
- lsmcontext_init(&context, secdata, seclen, 0);
+ put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
+ context.context);
security_release_secctx(&context);
}
}
diff --git a/kernel/audit.c b/kernel/audit.c
index c17ec23158c4..841123390d41 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1190,9 +1190,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
struct audit_sig_info *sig_data;
- char *ctx = NULL;
- u32 len;
- struct lsmcontext scaff; /* scaffolding */

err = audit_netlink_ok(skb, msg_type);
if (err)
@@ -1440,33 +1437,34 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
kfree(new);
break;
}
- case AUDIT_SIGNAL_INFO:
- len = 0;
+ case AUDIT_SIGNAL_INFO: {
+ struct lsmcontext context = { };
+ int len = 0;
+
if (lsmblob_is_set(&audit_sig_lsm)) {
- err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
- &len);
+ err = security_secid_to_secctx(&audit_sig_lsm,
+ &context);
if (err)
return err;
}
- sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+ sig_data = kmalloc(sizeof(*sig_data) + context.len, GFP_KERNEL);
if (!sig_data) {
- if (lsmblob_is_set(&audit_sig_lsm)) {
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
- }
+ if (lsmblob_is_set(&audit_sig_lsm))
+ security_release_secctx(&context);
return -ENOMEM;
}
sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
sig_data->pid = audit_sig_pid;
if (lsmblob_is_set(&audit_sig_lsm)) {
- memcpy(sig_data->ctx, ctx, len);
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
+ len = context.len;
+ memcpy(sig_data->ctx, context.context, len);
+ security_release_secctx(&context);
}
audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
sig_data, sizeof(*sig_data) + len);
kfree(sig_data);
break;
+ }
case AUDIT_TTY_GET: {
struct audit_tty_status s;
unsigned int t;
@@ -2132,26 +2130,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)

int audit_log_task_context(struct audit_buffer *ab)
{
- char *ctx = NULL;
- unsigned len;
int error;
struct lsmblob blob;
- struct lsmcontext scaff; /* scaffolding */
+ struct lsmcontext context;

security_task_getsecid_subj(current, &blob);
if (!lsmblob_is_set(&blob))
return 0;

- error = security_secid_to_secctx(&blob, &ctx, &len);
+ error = security_secid_to_secctx(&blob, &context);
if (error) {
if (error != -EINVAL)
goto error_path;
return 0;
}

- audit_log_format(ab, " subj=%s", ctx);
- lsmcontext_init(&scaff, ctx, len, 0);
- security_release_secctx(&scaff);
+ audit_log_format(ab, " subj=%s", context.context);
+ security_release_secctx(&context);
return 0;

error_path:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 1b1ddd62de6c..d198f307a4d8 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1002,9 +1002,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
struct lsmblob *blob, char *comm)
{
struct audit_buffer *ab;
- struct lsmcontext lsmcxt;
- char *ctx = NULL;
- u32 len;
+ struct lsmcontext lsmctx;
int rc = 0;

ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -1015,13 +1013,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (lsmblob_is_set(blob)) {
- if (security_secid_to_secctx(blob, &ctx, &len)) {
+ if (security_secid_to_secctx(blob, &lsmctx)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
- security_release_secctx(&lsmcxt);
+ audit_log_format(ab, " obj=%s", lsmctx.context);
+ security_release_secctx(&lsmctx);
}
}
audit_log_format(ab, " ocomm=");
@@ -1234,7 +1231,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)

static void show_special(struct audit_context *context, int *call_panic)
{
- struct lsmcontext lsmcxt;
struct audit_buffer *ab;
int i;

@@ -1259,17 +1255,15 @@ static void show_special(struct audit_context *context, int *call_panic)
from_kgid(&init_user_ns, context->ipc.gid),
context->ipc.mode);
if (osid) {
- char *ctx = NULL;
- u32 len;
+ struct lsmcontext lsmcxt;
struct lsmblob blob;

lsmblob_init(&blob, osid);
- if (security_secid_to_secctx(&blob, &ctx, &len)) {
+ if (security_secid_to_secctx(&blob, &lsmcxt)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0);
+ audit_log_format(ab, " obj=%s", lsmcxt.context);
security_release_secctx(&lsmcxt);
}
}
@@ -1418,20 +1412,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
MAJOR(n->rdev),
MINOR(n->rdev));
if (n->osid != 0) {
- char *ctx = NULL;
- u32 len;
struct lsmblob blob;
- struct lsmcontext lsmcxt;
+ struct lsmcontext lsmctx;

lsmblob_init(&blob, n->osid);
- if (security_secid_to_secctx(&blob, &ctx, &len)) {
+ if (security_secid_to_secctx(&blob, &lsmctx)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
- security_release_secctx(&lsmcxt);
+ audit_log_format(ab, " obj=%s", lsmctx.context);
+ security_release_secctx(&lsmctx);
}
}

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index a7e4c1b34b6c..ae073b642fa7 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -132,8 +132,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
{
struct lsmcontext context;
struct lsmblob lb;
- char *secdata;
- u32 seclen, secid;
+ u32 secid;
int err;

err = security_socket_getpeersec_dgram(NULL, skb, &secid);
@@ -141,12 +140,11 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
return;

lsmblob_init(&lb, secid);
- err = security_secid_to_secctx(&lb, &secdata, &seclen);
+ err = security_secid_to_secctx(&lb, &context);
if (err)
return;

- put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
- lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
+ put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
security_release_secctx(&context);
}

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 89be957f26bd..668b31ecd638 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -339,8 +339,7 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
{
struct nlattr *nest_secctx;
- int len, ret;
- char *secctx;
+ int ret;
struct lsmblob blob;
struct lsmcontext context;

@@ -348,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &secctx, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return 0;

@@ -357,13 +356,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
if (!nest_secctx)
goto nla_put_failure;

- if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
+ if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
goto nla_put_failure;
nla_nest_end(skb, nest_secctx);

ret = 0;
nla_put_failure:
- lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
security_release_secctx(&context);
return ret;
}
@@ -658,15 +656,15 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
#ifdef CONFIG_NF_CONNTRACK_SECMARK
int len, ret;
struct lsmblob blob;
+ struct lsmcontext context;

- /* lsmblob_init() puts ct->secmark into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, NULL, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return 0;

+ len = context.len;
+ security_release_secctx(&context);
+
return nla_total_size(0) /* CTA_SECCTX */
+ nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
#else
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index ca2ae290d6ee..b5796a8e5e90 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
{
int ret;
- u32 len;
- char *secctx;
struct lsmblob blob;
struct lsmcontext context;

lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &secctx, &len);
+ ret = security_secid_to_secctx(&blob, &context);
if (ret)
return;

- seq_printf(s, "secctx=%s ", secctx);
+ seq_printf(s, "secctx=%s ", context.context);

- lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
security_release_secctx(&context);
}
#else
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 005900a0c397..d5cff4559237 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -306,6 +306,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
struct lsmblob blob;
+ struct lsmcontext context = { };

if (!skb || !sk_fullsock(skb->sk))
return 0;
@@ -317,10 +318,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, secdata, &seclen);
+ security_secid_to_secctx(&blob, &context);
+ *secdata = context.context;
}

read_unlock_bh(&skb->sk->sk_callback_lock);
+ seclen = context.len;
#endif
return seclen;
}
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 61346aaa2898..9910d3e9d287 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -375,8 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
struct lsmcontext context;
- char *secctx = NULL;
- u32 secctx_len;
struct lsmblob blob;

if (addr_len != sizeof(struct in_addr) &&
@@ -444,12 +442,9 @@ int netlbl_unlhsh_add(struct net *net,
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, secid);
- if (security_secid_to_secctx(&blob,
- &secctx,
- &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ if (security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
@@ -482,8 +477,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
@@ -510,11 +503,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
if (entry != NULL)
lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob,
- &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -553,8 +544,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
@@ -580,10 +569,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
if (entry != NULL)
lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob,
- &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " sec_obj=%s", secctx);
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " sec_obj=%s",
+ context.context);
security_release_secctx(&context);
}
audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
@@ -1106,8 +1094,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
struct lsmcontext context;
void *data;
u32 secid;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;

data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
@@ -1167,15 +1153,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, secid);
- ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
+ ret_val = security_secid_to_secctx(&blob, &context);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
NLBL_UNLABEL_A_SECCTX,
- secctx_len,
- secctx);
- /* scaffolding */
- lsmcontext_init(&context, secctx, secctx_len, 0);
+ context.len,
+ context.context);
security_release_secctx(&context);
if (ret_val != 0)
goto list_cb_failure;
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index ef139d8ae7cd..951ba0639d20 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,8 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
{
struct audit_buffer *audit_buf;
struct lsmcontext context;
- char *secctx;
- u32 secctx_len;
struct lsmblob blob;

if (audit_enabled == AUDIT_OFF)
@@ -102,9 +100,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,

lsmblob_init(&blob, audit_info->secid);
if (audit_info->secid != 0 &&
- security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
- audit_log_format(audit_buf, " subj=%s", secctx);
- lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
+ security_secid_to_secctx(&blob, &context) == 0) {
+ audit_log_format(audit_buf, " subj=%s", context.context);
security_release_secctx(&context);
}

diff --git a/security/security.c b/security/security.c
index 4cb540d93ab8..713e0340a0d4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2325,18 +2325,22 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);

-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
struct security_hook_list *hp;
int ilsm = lsm_task_ilsm(current);

+ memset(cp, 0, sizeof(*cp));
+
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot)
+ if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) {
+ cp->slot = hp->lsmid->slot;
return hp->hook.secid_to_secctx(
blob->secid[hp->lsmid->slot],
- secdata, seclen);
+ &cp->context, &cp->len);
+ }
}

return LSM_RET_DEFAULT(secid_to_secctx);
--
2.31.1

2021-07-22 01:09:05

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 18/25] LSM: security_secid_to_secctx in netlink netfilter

Change netlink netfilter interfaces to use lsmcontext
pointers, and remove scaffolding.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Paul Moore <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
net/netfilter/nfnetlink_queue.c | 37 +++++++++++++--------------------
1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index d5cff4559237..cffb04baf7b8 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
return -1;
}

-static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
+static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
{
- u32 seclen = 0;
#if IS_ENABLED(CONFIG_NETWORK_SECMARK)
struct lsmblob blob;
- struct lsmcontext context = { };

if (!skb || !sk_fullsock(skb->sk))
- return 0;
+ return;

read_lock_bh(&skb->sk->sk_callback_lock);

@@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, &context);
- *secdata = context.context;
+ security_secid_to_secctx(&blob, context);
}

read_unlock_bh(&skb->sk->sk_callback_lock);
- seclen = context.len;
#endif
- return seclen;
+ return;
}

static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
@@ -397,12 +393,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
struct net_device *indev;
struct net_device *outdev;
struct nf_conn *ct = NULL;
+ struct lsmcontext context = { };
enum ip_conntrack_info ctinfo;
struct nfnl_ct_hook *nfnl_ct;
bool csum_verify;
- struct lsmcontext scaff; /* scaffolding */
- char *secdata = NULL;
- u32 seclen = 0;

size = nlmsg_total_size(sizeof(struct nfgenmsg))
+ nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
@@ -470,9 +464,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}

if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
- seclen = nfqnl_get_sk_secctx(entskb, &secdata);
- if (seclen)
- size += nla_total_size(seclen);
+ nfqnl_get_sk_secctx(entskb, &context);
+ if (context.len)
+ size += nla_total_size(context.len);
}

skb = alloc_skb(size, GFP_ATOMIC);
@@ -602,7 +596,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
goto nla_put_failure;

- if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
+ if (context.len &&
+ nla_put(skb, NFQA_SECCTX, context.len, context.context))
goto nla_put_failure;

if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
@@ -630,10 +625,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}

nlh->nlmsg_len = skb->len;
- if (seclen) {
- lsmcontext_init(&scaff, secdata, seclen, 0);
- security_release_secctx(&scaff);
- }
+ if (context.len)
+ security_release_secctx(&context);
return skb;

nla_put_failure:
@@ -641,10 +634,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
kfree_skb(skb);
net_err_ratelimited("nf_queue: error creating packet message\n");
nlmsg_failure:
- if (seclen) {
- lsmcontext_init(&scaff, secdata, seclen, 0);
- security_release_secctx(&scaff);
- }
+ if (context.len)
+ security_release_secctx(&context);
return NULL;
}

--
2.31.1

2021-07-22 01:11:18

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 19/25] NET: Store LSM netlabel data in a lsmblob

Netlabel uses LSM interfaces requiring an lsmblob and
the internal storage is used to pass information between
these interfaces, so change the internal data from a secid
to a lsmblob. Update the netlabel interfaces and their
callers to accommodate the change. This requires that the
modules using netlabel use the lsm_id.slot to access the
correct secid when using netlabel.

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
---
include/net/netlabel.h | 8 +--
net/ipv4/cipso_ipv4.c | 26 ++++++----
net/netlabel/netlabel_kapi.c | 6 +--
net/netlabel/netlabel_unlabeled.c | 79 +++++++++--------------------
net/netlabel/netlabel_unlabeled.h | 2 +-
security/selinux/hooks.c | 2 +-
security/selinux/include/security.h | 1 +
security/selinux/netlabel.c | 2 +-
security/selinux/ss/services.c | 4 +-
security/smack/smack.h | 1 +
security/smack/smack_access.c | 2 +-
security/smack/smack_lsm.c | 11 ++--
security/smack/smackfs.c | 10 ++--
13 files changed, 68 insertions(+), 86 deletions(-)

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 43ae50337685..73fc25b4042b 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -166,7 +166,7 @@ struct netlbl_lsm_catmap {
* @attr.mls: MLS sensitivity label
* @attr.mls.cat: MLS category bitmap
* @attr.mls.lvl: MLS sensitivity level
- * @attr.secid: LSM specific secid token
+ * @attr.lsmblob: LSM specific data
*
* Description:
* This structure is used to pass security attributes between NetLabel and the
@@ -201,7 +201,7 @@ struct netlbl_lsm_secattr {
struct netlbl_lsm_catmap *cat;
u32 lvl;
} mls;
- u32 secid;
+ struct lsmblob lsmblob;
} attr;
};

@@ -415,7 +415,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_cfg_unlbl_static_del(struct net *net,
const char *dev_name,
@@ -523,7 +523,7 @@ static inline int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
return -ENOSYS;
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 099259fc826a..9bd72ec01785 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -106,15 +106,17 @@ int cipso_v4_rbm_strictvalid = 1;
/* Base length of the local tag (non-standard tag).
* Tag definition (may change between kernel versions)
*
- * 0 8 16 24 32
- * +----------+----------+----------+----------+
- * | 10000000 | 00000110 | 32-bit secid value |
- * +----------+----------+----------+----------+
- * | in (host byte order)|
- * +----------+----------+
- *
+ * 0 8 16 16 + sizeof(struct lsmblob)
+ * +----------+----------+---------------------+
+ * | 10000000 | 00000110 | LSM blob data |
+ * +----------+----------+---------------------+
+ *
+ * All secid and flag fields are in host byte order.
+ * The lsmblob structure size varies depending on which
+ * Linux security modules are built in the kernel.
+ * The data is opaque.
*/
-#define CIPSO_V4_TAG_LOC_BLEN 6
+#define CIPSO_V4_TAG_LOC_BLEN (2 + sizeof(struct lsmblob))

/*
* Helper Functions
@@ -1460,7 +1462,11 @@ static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,

buffer[0] = CIPSO_V4_TAG_LOCAL;
buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
- *(u32 *)&buffer[2] = secattr->attr.secid;
+ /* Ensure that there is sufficient space in the CIPSO header
+ * for the LSM data. */
+ BUILD_BUG_ON(CIPSO_V4_TAG_LOC_BLEN > CIPSO_V4_OPT_LEN_MAX);
+ memcpy(&buffer[2], &secattr->attr.lsmblob,
+ sizeof(secattr->attr.lsmblob));

return CIPSO_V4_TAG_LOC_BLEN;
}
@@ -1480,7 +1486,7 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
const unsigned char *tag,
struct netlbl_lsm_secattr *secattr)
{
- secattr->attr.secid = *(u32 *)&tag[2];
+ memcpy(&secattr->attr.lsmblob, &tag[2], sizeof(secattr->attr.lsmblob));
secattr->flags |= NETLBL_SECATTR_SECID;

return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index beb0e573266d..158bab993e32 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -196,7 +196,7 @@ int netlbl_cfg_unlbl_map_add(const char *domain,
* @addr: IP address in network byte order (struct in[6]_addr)
* @mask: address mask in network byte order (struct in[6]_addr)
* @family: address family
- * @secid: LSM secid value for the entry
+ * @lsmblob: LSM data value for the entry
* @audit_info: NetLabel audit information
*
* Description:
@@ -210,7 +210,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,
const void *addr,
const void *mask,
u16 family,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
u32 addr_len;
@@ -230,7 +230,7 @@ int netlbl_cfg_unlbl_static_add(struct net *net,

return netlbl_unlhsh_add(net,
dev_name, addr, mask, addr_len,
- secid, audit_info);
+ lsmblob, audit_info);
}

/**
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 9910d3e9d287..289602835b75 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -66,7 +66,7 @@ struct netlbl_unlhsh_tbl {
#define netlbl_unlhsh_addr4_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr4, list)
struct netlbl_unlhsh_addr4 {
- u32 secid;
+ struct lsmblob lsmblob;

struct netlbl_af4list list;
struct rcu_head rcu;
@@ -74,7 +74,7 @@ struct netlbl_unlhsh_addr4 {
#define netlbl_unlhsh_addr6_entry(iter) \
container_of(iter, struct netlbl_unlhsh_addr6, list)
struct netlbl_unlhsh_addr6 {
- u32 secid;
+ struct lsmblob lsmblob;

struct netlbl_af6list list;
struct rcu_head rcu;
@@ -220,7 +220,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
* @iface: the associated interface entry
* @addr: IPv4 address in network byte order
* @mask: IPv4 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -231,7 +231,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
const struct in_addr *addr,
const struct in_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr4 *entry;
@@ -243,7 +243,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
entry->list.addr = addr->s_addr & mask->s_addr;
entry->list.mask = mask->s_addr;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;

spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);
@@ -260,7 +260,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
* @iface: the associated interface entry
* @addr: IPv6 address in network byte order
* @mask: IPv6 address mask in network byte order
- * @secid: LSM secid value for entry
+ * @lsmblob: LSM data value for entry
*
* Description:
* Add a new address entry into the unlabeled connection hash table using the
@@ -271,7 +271,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
const struct in6_addr *addr,
const struct in6_addr *mask,
- u32 secid)
+ struct lsmblob *lsmblob)
{
int ret_val;
struct netlbl_unlhsh_addr6 *entry;
@@ -287,7 +287,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
entry->list.mask = *mask;
entry->list.valid = 1;
- entry->secid = secid;
+ entry->lsmblob = *lsmblob;

spin_lock(&netlbl_unlhsh_lock);
ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);
@@ -366,7 +366,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info)
{
int ret_val;
@@ -375,7 +375,6 @@ int netlbl_unlhsh_add(struct net *net,
struct netlbl_unlhsh_iface *iface;
struct audit_buffer *audit_buf = NULL;
struct lsmcontext context;
- struct lsmblob blob;

if (addr_len != sizeof(struct in_addr) &&
addr_len != sizeof(struct in6_addr))
@@ -408,7 +407,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in_addr *addr4 = addr;
const struct in_addr *mask4 = mask;

- ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
+ ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, lsmblob);
if (audit_buf != NULL)
netlbl_af4list_audit_addr(audit_buf, 1,
dev_name,
@@ -421,7 +420,7 @@ int netlbl_unlhsh_add(struct net *net,
const struct in6_addr *addr6 = addr;
const struct in6_addr *mask6 = mask;

- ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
+ ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, lsmblob);
if (audit_buf != NULL)
netlbl_af6list_audit_addr(audit_buf, 1,
dev_name,
@@ -438,11 +437,7 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- /* lsmblob_init() puts secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- if (security_secid_to_secctx(&blob, &context) == 0) {
+ if (security_secid_to_secctx(lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -477,7 +472,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
@@ -497,13 +491,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
addr->s_addr, mask->s_addr);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -544,7 +533,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
struct audit_buffer *audit_buf;
struct net_device *dev;
struct lsmcontext context;
- struct lsmblob blob;

spin_lock(&netlbl_unlhsh_lock);
list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
@@ -563,13 +551,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
addr, mask);
if (dev != NULL)
dev_put(dev);
- /* lsmblob_init() puts entry->secid into all of the secids
- * in blob. security_secid_to_secctx() will know which
- * security module to use to create the secctx. */
- if (entry != NULL)
- lsmblob_init(&blob, entry->secid);
if (entry != NULL &&
- security_secid_to_secctx(&blob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -923,14 +906,8 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;

- /* netlbl_unlhsh_add will be changed to pass a struct lsmblob *
- * instead of a u32 later in this patch set. security_secctx_to_secid()
- * will only be setting one entry in the lsmblob struct, so it is
- * safe to use lsmblob_value() to get that one value. */
-
- return netlbl_unlhsh_add(&init_net,
- dev_name, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, dev_name, addr, mask, addr_len,
+ &blob, &audit_info);
}

/**
@@ -977,11 +954,8 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
if (ret_val != 0)
return ret_val;

- /* security_secctx_to_secid() will only put one secid into the lsmblob
- * so it's safe to use lsmblob_value() to get the secid. */
- return netlbl_unlhsh_add(&init_net,
- NULL, addr, mask, addr_len,
- lsmblob_value(&blob), &audit_info);
+ return netlbl_unlhsh_add(&init_net, NULL, addr, mask, addr_len, &blob,
+ &audit_info);
}

/**
@@ -1093,8 +1067,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
struct net_device *dev;
struct lsmcontext context;
void *data;
- u32 secid;
- struct lsmblob blob;
+ struct lsmblob *lsmb;

data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_unlabel_gnl_family,
@@ -1132,7 +1105,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;

- secid = addr4->secid;
+ lsmb = (struct lsmblob *)&addr4->lsmblob;
} else {
ret_val = nla_put_in6_addr(cb_arg->skb,
NLBL_UNLABEL_A_IPV6ADDR,
@@ -1146,14 +1119,10 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
if (ret_val != 0)
goto list_cb_failure;

- secid = addr6->secid;
+ lsmb = (struct lsmblob *)&addr6->lsmblob;
}

- /* lsmblob_init() secid into all of the secids in blob.
- * security_secid_to_secctx() will know which security module
- * to use to create the secctx. */
- lsmblob_init(&blob, secid);
- ret_val = security_secid_to_secctx(&blob, &context);
+ ret_val = security_secid_to_secctx(lsmb, &context);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
@@ -1512,7 +1481,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr4_list);
if (addr4 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr4_entry(addr4)->lsmblob;
break;
}
#if IS_ENABLED(CONFIG_IPV6)
@@ -1525,7 +1494,7 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
&iface->addr6_list);
if (addr6 == NULL)
goto unlabel_getattr_nolabel;
- secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;
+ secattr->attr.lsmblob = netlbl_unlhsh_addr6_entry(addr6)->lsmblob;
break;
}
#endif /* IPv6 */
diff --git a/net/netlabel/netlabel_unlabeled.h b/net/netlabel/netlabel_unlabeled.h
index 058e3a285d56..168920780994 100644
--- a/net/netlabel/netlabel_unlabeled.h
+++ b/net/netlabel/netlabel_unlabeled.h
@@ -211,7 +211,7 @@ int netlbl_unlhsh_add(struct net *net,
const void *addr,
const void *mask,
u32 addr_len,
- u32 secid,
+ struct lsmblob *lsmblob,
struct netlbl_audit *audit_info);
int netlbl_unlhsh_remove(struct net *net,
const char *dev_name,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 3b95eb39a3bf..12ae311b7275 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7112,7 +7112,7 @@ static int selinux_perf_event_write(struct perf_event *event)
}
#endif

-static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
+struct lsm_id selinux_lsmid __lsm_ro_after_init = {
.lsm = "selinux",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ac0ece01305a..9f856f2cd277 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -73,6 +73,7 @@
struct netlbl_lsm_secattr;

extern int selinux_enabled_boot;
+extern struct lsm_id selinux_lsmid;

/*
* type_datum properties
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 6a94b31b5472..d8d7603ab14e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -108,7 +108,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
return NULL;

if ((secattr->flags & NETLBL_SECATTR_SECID) &&
- (secattr->attr.secid == sid))
+ (secattr->attr.lsmblob.secid[selinux_lsmid.slot] == sid))
return secattr;

return NULL;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index d84c77f370dc..f6be8cd7666b 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -3899,7 +3899,7 @@ int security_netlbl_secattr_to_sid(struct selinux_state *state,
if (secattr->flags & NETLBL_SECATTR_CACHE)
*sid = *(u32 *)secattr->cache->data;
else if (secattr->flags & NETLBL_SECATTR_SECID)
- *sid = secattr->attr.secid;
+ *sid = secattr->attr.lsmblob.secid[selinux_lsmid.slot];
else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
rc = -EIDRM;
ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
@@ -3977,7 +3977,7 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
if (secattr->domain == NULL)
goto out;

- secattr->attr.secid = sid;
+ secattr->attr.lsmblob.secid[selinux_lsmid.slot] = sid;
secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
mls_export_netlbl_lvl(policydb, ctx, secattr);
rc = mls_export_netlbl_cat(policydb, ctx, secattr);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index b5bdf947792f..0eaae6b3f935 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -303,6 +303,7 @@ int smack_populate_secattr(struct smack_known *skp);
* Shared data.
*/
extern int smack_enabled;
+extern struct lsm_id smack_lsmid;
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 1f391f6a3d47..ceea74bbaedc 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -525,7 +525,7 @@ int smack_populate_secattr(struct smack_known *skp)
{
int slen;

- skp->smk_netlabel.attr.secid = skp->smk_secid;
+ skp->smk_netlabel.attr.lsmblob.secid[smack_lsmid.slot] = skp->smk_secid;
skp->smk_netlabel.domain = skp->smk_known;
skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
if (skp->smk_netlabel.cache != NULL) {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 7aa7ea38f627..e65497a5c095 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3720,11 +3720,12 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
return (struct smack_known *)sap->cache->data;

+ /*
+ * Looks like a fallback, which gives us a secid.
+ */
if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
- /*
- * Looks like a fallback, which gives us a secid.
- */
- return smack_from_secid(sap->attr.secid);
+ return smack_from_secid(
+ sap->attr.lsmblob.secid[smack_lsmid.slot]);

if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
/*
@@ -4701,7 +4702,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_superblock = sizeof(struct superblock_smack),
};

-static struct lsm_id smack_lsmid __lsm_ro_after_init = {
+struct lsm_id smack_lsmid __lsm_ro_after_init = {
.lsm = "smack",
.slot = LSMBLOB_NEEDED
};
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 3a75d2a8f517..9cda52f2ec31 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1142,6 +1142,7 @@ static void smk_net4addr_insert(struct smk_net4addr *new)
static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
+ struct lsmblob lsmblob;
struct smk_net4addr *snp;
struct sockaddr_in newname;
char *smack;
@@ -1273,10 +1274,13 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
* this host so that incoming packets get labeled.
* but only if we didn't get the special CIPSO option
*/
- if (rc == 0 && skp != NULL)
+ if (rc == 0 && skp != NULL) {
+ lsmblob_init(&lsmblob, 0);
+ lsmblob.secid[smack_lsmid.slot] = snp->smk_label->smk_secid;
rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
- &snp->smk_host, &snp->smk_mask, PF_INET,
- snp->smk_label->smk_secid, &audit_info);
+ &snp->smk_host, &snp->smk_mask, PF_INET, &lsmblob,
+ &audit_info);
+ }

if (rc == 0)
rc = count;
--
2.31.1

2021-07-22 01:11:19

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 20/25] LSM: Verify LSM display sanity in binder

Verify that the tasks on the ends of a binder transaction
use the same "interface_lsm" security module. This prevents
confusion of security "contexts".

Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: Paul Moore <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
---
security/security.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/security/security.c b/security/security.c
index 13ded9c55344..cb359e185d1a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -859,9 +859,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr)
return call_int_hook(binder_set_context_mgr, 0, mgr);
}

+/**
+ * security_binder_transaction - Binder driver transaction check
+ * @from: source of the transaction
+ * @to: destination of the transaction
+ *
+ * Verify that the tasks have the same LSM "display", then
+ * call the security module hooks.
+ *
+ * Returns -EINVAL if the displays don't match, or the
+ * result of the security module checks.
+ */
int security_binder_transaction(struct task_struct *from,
struct task_struct *to)
{
+ int from_ilsm = lsm_task_ilsm(from);
+ int to_ilsm = lsm_task_ilsm(to);
+
+ /*
+ * If the ilsm is LSMBLOB_INVALID the first module that has
+ * an entry is used. This will be in the 0 slot.
+ *
+ * This is currently only required if the server has requested
+ * peer contexts, but it would be unwieldly to have too much of
+ * the binder driver detail here.
+ */
+ if (from_ilsm == LSMBLOB_INVALID)
+ from_ilsm = 0;
+ if (to_ilsm == LSMBLOB_INVALID)
+ to_ilsm = 0;
+ if (from_ilsm != to_ilsm)
+ return -EINVAL;
+
return call_int_hook(binder_transaction, 0, from, to);
}

--
2.31.1

2021-07-22 01:13:00

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 21/25] audit: support non-syscall auxiliary records

Standalone audit records have the timestamp and serial number generated
on the fly and as such are unique, making them standalone. This new
function audit_alloc_local() generates a local audit context that will
be used only for a standalone record and its auxiliary record(s). The
context is discarded immediately after the local associated records are
produced.

Acked-by: Paul Moore <[email protected]>
Signed-off-by: Richard Guy Briggs <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
To: Richard Guy Briggs <[email protected]>
---
include/linux/audit.h | 8 ++++++++
kernel/audit.h | 1 +
kernel/auditsc.c | 33 ++++++++++++++++++++++++++++-----
3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 418a485af114..97cd7471e572 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -289,6 +289,8 @@ static inline int audit_signal_info(int sig, struct task_struct *t)
/* Public API */
extern int audit_alloc(struct task_struct *task);
extern void __audit_free(struct task_struct *task);
+extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
+extern void audit_free_context(struct audit_context *context);
extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
unsigned long a2, unsigned long a3);
extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -552,6 +554,12 @@ static inline void audit_log_nfcfg(const char *name, u8 af,
extern int audit_n_rules;
extern int audit_signals;
#else /* CONFIG_AUDITSYSCALL */
++static inline struct audit_context *audit_alloc_local(gfp_t gfpflags)
+{
+ return NULL;
+}
+static inline void audit_free_context(struct audit_context *context)
+{ }
static inline int audit_alloc(struct task_struct *task)
{
return 0;
diff --git a/kernel/audit.h b/kernel/audit.h
index b679517a3030..ddc1a69edc79 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -99,6 +99,7 @@ struct audit_proctitle {
struct audit_context {
int dummy; /* must be the first element */
int in_syscall; /* 1 if task is in a syscall */
+ bool local; /* local context needed */
enum audit_state state, current_state;
unsigned int serial; /* serial number for record */
int major; /* syscall number */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d198f307a4d8..0e58a3ab56f5 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -931,11 +931,13 @@ static inline void audit_free_aux(struct audit_context *context)
}
}

-static inline struct audit_context *audit_alloc_context(enum audit_state state)
+static inline struct audit_context *audit_alloc_context(enum audit_state state,
+ gfp_t gfpflags)
{
struct audit_context *context;

- context = kzalloc(sizeof(*context), GFP_KERNEL);
+ /* We can be called in atomic context via audit_tg() */
+ context = kzalloc(sizeof(*context), gfpflags);
if (!context)
return NULL;
context->state = state;
@@ -971,7 +973,8 @@ int audit_alloc(struct task_struct *tsk)
return 0;
}

- if (!(context = audit_alloc_context(state))) {
+ context = audit_alloc_context(state, GFP_KERNEL);
+ if (!context) {
kfree(key);
audit_log_lost("out of memory in audit_alloc");
return -ENOMEM;
@@ -983,8 +986,27 @@ int audit_alloc(struct task_struct *tsk)
return 0;
}

-static inline void audit_free_context(struct audit_context *context)
+struct audit_context *audit_alloc_local(gfp_t gfpflags)
{
+ struct audit_context *context = NULL;
+
+ context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
+ if (!context) {
+ audit_log_lost("out of memory in audit_alloc_local");
+ goto out;
+ }
+ context->serial = audit_serial();
+ ktime_get_coarse_real_ts64(&context->ctime);
+ context->local = true;
+out:
+ return context;
+}
+EXPORT_SYMBOL(audit_alloc_local);
+
+void audit_free_context(struct audit_context *context)
+{
+ if (!context)
+ return;
audit_free_module(context);
audit_free_names(context);
unroll_tree_refs(context, NULL, 0);
@@ -995,6 +1017,7 @@ static inline void audit_free_context(struct audit_context *context)
audit_proctitle_free(context);
kfree(context);
}
+EXPORT_SYMBOL(audit_free_context);

static int audit_log_pid_context(struct audit_context *context, pid_t pid,
kuid_t auid, kuid_t uid,
@@ -2223,7 +2246,7 @@ EXPORT_SYMBOL_GPL(__audit_inode_child);
int auditsc_get_stamp(struct audit_context *ctx,
struct timespec64 *t, unsigned int *serial)
{
- if (!ctx->in_syscall)
+ if (!ctx->in_syscall && !ctx->local)
return 0;
if (!ctx->serial)
ctx->serial = audit_serial();
--
2.31.1

2021-07-22 01:14:13

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 22/25] Audit: Add record for multiple process LSM attributes

Create a new audit record type to contain the subject information
when there are multiple security modules that require such data.
This record is linked with the same timestamp and serial number
using the audit_alloc_local() mechanism.
The record is produced only in cases where there is more than one
security module with a process "context".
In cases where this record is produced the subj= fields of
other records in the audit event will be set to "subj=?".

An example of the MAC_TASK_CONTEXTS (1420) record is:

type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor="=unconfined"
subj_smack="_"

There will be a subj_$LSM= entry for each security module
LSM that supports the secid_to_secctx and secctx_to_secid
hooks. The BPF security module implements secid/secctx
translation hooks, so it has to be considered to provide a
secctx even though it may not actually do so.

Signed-off-by: Casey Schaufler <[email protected]>
To: [email protected]
To: [email protected]
To: [email protected]
Cc: [email protected]
---
drivers/android/binder.c | 2 +-
include/linux/audit.h | 16 +++++
include/linux/security.h | 16 ++++-
include/net/netlabel.h | 2 +-
include/net/scm.h | 2 +-
include/net/xfrm.h | 13 +++-
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 90 +++++++++++++++++++------
kernel/auditfilter.c | 5 +-
kernel/auditsc.c | 27 ++++++--
net/ipv4/ip_sockglue.c | 2 +-
net/netfilter/nf_conntrack_netlink.c | 4 +-
net/netfilter/nf_conntrack_standalone.c | 2 +-
net/netfilter/nfnetlink_queue.c | 2 +-
net/netlabel/netlabel_unlabeled.c | 21 +++---
net/netlabel/netlabel_user.c | 14 ++--
net/netlabel/netlabel_user.h | 6 +-
net/xfrm/xfrm_policy.c | 8 ++-
net/xfrm/xfrm_state.c | 18 +++--
security/integrity/ima/ima_api.c | 6 +-
security/integrity/integrity_audit.c | 5 +-
security/security.c | 46 ++++++++-----
security/smack/smackfs.c | 3 +-
23 files changed, 221 insertions(+), 90 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 2c3a2348a144..3520caa0260c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2722,7 +2722,7 @@ static void binder_transaction(struct binder_proc *proc,
* case well anyway.
*/
security_task_getsecid_obj(proc->tsk, &blob);
- ret = security_secid_to_secctx(&blob, &lsmctx);
+ ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY);
if (ret) {
return_error = BR_FAILED_REPLY;
return_error_param = ret;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 97cd7471e572..85eb87f6f92d 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -291,6 +291,7 @@ extern int audit_alloc(struct task_struct *task);
extern void __audit_free(struct task_struct *task);
extern struct audit_context *audit_alloc_local(gfp_t gfpflags);
extern void audit_free_context(struct audit_context *context);
+extern void audit_free_local(struct audit_context *context);
extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1,
unsigned long a2, unsigned long a3);
extern void __audit_syscall_exit(int ret_success, long ret_value);
@@ -386,6 +387,19 @@ static inline void audit_ptrace(struct task_struct *t)
__audit_ptrace(t);
}

+static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp)
+{
+ struct audit_context *context = audit_context();
+
+ if (context)
+ return context;
+
+ if (lsm_multiple_contexts())
+ return audit_alloc_local(gfp);
+
+ return NULL;
+}
+
/* Private API (for audit.c only) */
extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
@@ -560,6 +574,8 @@ extern int audit_signals;
}
static inline void audit_free_context(struct audit_context *context)
{ }
+static inline void audit_free_local(struct audit_context *context)
+{ }
static inline int audit_alloc(struct task_struct *task)
{
return 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index 3e9743118fb9..b3cf68cf2bd6 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -182,6 +182,8 @@ struct lsmblob {
#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */
#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */
#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */
+#define LSMBLOB_DISPLAY -4 /* Use the "display" slot */
+#define LSMBLOB_FIRST -5 /* Use the default "display" slot */

/**
* lsmblob_init - initialize an lsmblob structure
@@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob)
return 0;
}

+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+ return lsm_slot_to_name(1) != NULL;
+#else
+ return false;
+#endif
+}
+
/* These functions are in security/commoncap.c */
extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
int cap, unsigned int opts);
@@ -578,7 +589,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+ int display);
int security_secctx_to_secid(const char *secdata, u32 seclen,
struct lsmblob *blob);
void security_release_secctx(struct lsmcontext *cp);
@@ -1433,7 +1445,7 @@ static inline int security_ismaclabel(const char *name)
}

static inline int security_secid_to_secctx(struct lsmblob *blob,
- struct lsmcontext *cp)
+ struct lsmcontext *cp, int display)
{
return -EOPNOTSUPP;
}
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 73fc25b4042b..216cb1ffc8f0 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -97,7 +97,7 @@ struct calipso_doi;

/* NetLabel audit information */
struct netlbl_audit {
- u32 secid;
+ struct lsmblob lsmdata;
kuid_t loginuid;
unsigned int sessionid;
};
diff --git a/include/net/scm.h b/include/net/scm.h
index b77a52f93389..f4d567d4885e 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
* and the infrastructure will know which it is.
*/
lsmblob_init(&lb, scm->secid);
- err = security_secid_to_secctx(&lb, &context);
+ err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);

if (!err) {
put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len,
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index cbff7c2a9724..a10fa01f7bf4 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -660,13 +660,22 @@ struct xfrm_spi_skb_cb {
#define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))

#ifdef CONFIG_AUDITSYSCALL
-static inline struct audit_buffer *xfrm_audit_start(const char *op)
+static inline struct audit_buffer *xfrm_audit_start(const char *op,
+ struct audit_context **lac)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf = NULL;

if (audit_enabled == AUDIT_OFF)
return NULL;
- audit_buf = audit_log_start(audit_context(), GFP_ATOMIC,
+ context = audit_context();
+ if (lac != NULL) {
+ if (lsm_multiple_contexts() && context == NULL)
+ context = audit_alloc_local(GFP_ATOMIC);
+ *lac = context;
+ }
+
+ audit_buf = audit_log_start(context, GFP_ATOMIC,
AUDIT_MAC_IPSEC_EVENT);
if (audit_buf == NULL)
return NULL;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index daa481729e9b..4432a8bed8e0 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -139,6 +139,7 @@
#define AUDIT_MAC_UNLBL_STCDEL 1417 /* NetLabel: del a static label */
#define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */
#define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */
+#define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM contexts */

#define AUDIT_FIRST_KERN_ANOM_MSG 1700
#define AUDIT_LAST_KERN_ANOM_MSG 1799
diff --git a/kernel/audit.c b/kernel/audit.c
index 841123390d41..cba63789a164 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -386,10 +386,12 @@ void audit_log_lost(const char *message)
static int audit_log_config_change(char *function_name, u32 new, u32 old,
int allow_changes)
{
+ struct audit_context *context;
struct audit_buffer *ab;
int rc = 0;

- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (unlikely(!ab))
return rc;
audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
@@ -399,6 +401,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old,
allow_changes = 0; /* Something weird, deny request */
audit_log_format(ab, " res=%d", allow_changes);
audit_log_end(ab);
+ audit_free_local(context);
return rc;
}

@@ -1072,12 +1075,6 @@ static void audit_log_common_recv_msg(struct audit_context *context,
audit_log_task_context(*ab);
}

-static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
- u16 msg_type)
-{
- audit_log_common_recv_msg(NULL, ab, msg_type);
-}
-
int is_audit_feature_set(int i)
{
return af.features & AUDIT_FEATURE_TO_MASK(i);
@@ -1190,6 +1187,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
struct audit_sig_info *sig_data;
+ struct audit_context *lcontext;

err = audit_netlink_ok(skb, msg_type);
if (err)
@@ -1357,7 +1355,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (err)
break;
}
- audit_log_user_recv_msg(&ab, msg_type);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, msg_type);
if (msg_type != AUDIT_USER_TTY) {
/* ensure NULL termination */
str[data_len - 1] = '\0';
@@ -1371,6 +1370,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
audit_log_n_untrustedstring(ab, str, data_len);
}
audit_log_end(ab);
+ audit_free_local(lcontext);
}
break;
case AUDIT_ADD_RULE:
@@ -1378,13 +1378,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (data_len < sizeof(struct audit_rule_data))
return -EINVAL;
if (audit_enabled == AUDIT_LOCKED) {
- audit_log_common_recv_msg(audit_context(), &ab,
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=%s audit_enabled=%d res=0",
msg_type == AUDIT_ADD_RULE ?
"add_rule" : "remove_rule",
audit_enabled);
audit_log_end(ab);
+ audit_free_local(lcontext);
return -EPERM;
}
err = audit_rule_change(msg_type, seq, data, data_len);
@@ -1394,10 +1396,11 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
case AUDIT_TRIM:
audit_trim_trees();
- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=trim res=1");
audit_log_end(ab);
+ audit_free_local(lcontext);
break;
case AUDIT_MAKE_EQUIV: {
void *bufp = data;
@@ -1425,14 +1428,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
/* OK, here comes... */
err = audit_tag_tree(old, new);

- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=make_equiv old=");
audit_log_untrustedstring(ab, old);
audit_log_format(ab, " new=");
audit_log_untrustedstring(ab, new);
audit_log_format(ab, " res=%d", !err);
audit_log_end(ab);
+ audit_free_local(lcontext);
kfree(old);
kfree(new);
break;
@@ -1443,7 +1447,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)

if (lsmblob_is_set(&audit_sig_lsm)) {
err = security_secid_to_secctx(&audit_sig_lsm,
- &context);
+ &context, LSMBLOB_FIRST);
if (err)
return err;
}
@@ -1498,13 +1502,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
old.enabled = t & AUDIT_TTY_ENABLE;
old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);

- audit_log_common_recv_msg(audit_context(), &ab,
- AUDIT_CONFIG_CHANGE);
+ lcontext = audit_alloc_for_lsm(GFP_KERNEL);
+ audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
" old-log_passwd=%d new-log_passwd=%d res=%d",
old.enabled, s.enabled, old.log_passwd,
s.log_passwd, !err);
audit_log_end(ab);
+ audit_free_local(lcontext);
break;
}
default:
@@ -1550,6 +1555,7 @@ static void audit_receive(struct sk_buff *skb)
/* Log information about who is connecting to the audit multicast socket */
static void audit_log_multicast(int group, const char *op, int err)
{
+ struct audit_context *context;
const struct cred *cred;
struct tty_struct *tty;
char comm[sizeof(current->comm)];
@@ -1558,7 +1564,8 @@ static void audit_log_multicast(int group, const char *op, int err)
if (!audit_enabled)
return;

- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_EVENT_LISTENER);
if (!ab)
return;

@@ -1577,6 +1584,7 @@ static void audit_log_multicast(int group, const char *op, int err)
audit_log_d_path_exe(ab, current->mm); /* exe= */
audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
audit_log_end(ab);
+ audit_free_local(context);
}

/* Run custom bind function on netlink socket group connect or bind requests. */
@@ -2128,6 +2136,36 @@ void audit_log_key(struct audit_buffer *ab, char *key)
audit_log_format(ab, "(null)");
}

+static void audit_log_lsm(struct audit_context *context, struct lsmblob *blob)
+{
+ struct audit_buffer *ab;
+ struct lsmcontext lsmdata;
+ bool sep = false;
+ int error;
+ int i;
+
+ ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS);
+ if (!ab)
+ return; /* audit_panic or being filtered */
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (blob->secid[i] == 0)
+ continue;
+ error = security_secid_to_secctx(blob, &lsmdata, i);
+ if (error && error != -EINVAL) {
+ audit_panic("error in audit_log_lsm");
+ return;
+ }
+
+ audit_log_format(ab, "%ssubj_%s=\"%s\"", sep ? " " : "",
+ lsm_slot_to_name(i), lsmdata.context);
+ sep = true;
+
+ security_release_secctx(&lsmdata);
+ }
+ audit_log_end(ab);
+}
+
int audit_log_task_context(struct audit_buffer *ab)
{
int error;
@@ -2138,7 +2176,18 @@ int audit_log_task_context(struct audit_buffer *ab)
if (!lsmblob_is_set(&blob))
return 0;

- error = security_secid_to_secctx(&blob, &context);
+ /*
+ * If there is more than one security module that has a
+ * subject "context" it's necessary to put the subject data
+ * into a separate record to maintain compatibility.
+ */
+ if (lsm_multiple_contexts()) {
+ audit_log_format(ab, " subj=?");
+ audit_log_lsm(ab->ctx, &blob);
+ return 0;
+ }
+
+ error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
if (error) {
if (error != -EINVAL)
goto error_path;
@@ -2274,6 +2323,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
unsigned int oldsessionid,
unsigned int sessionid, int rc)
{
+ struct audit_context *context;
struct audit_buffer *ab;
uid_t uid, oldloginuid, loginuid;
struct tty_struct *tty;
@@ -2281,7 +2331,8 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
if (!audit_enabled)
return;

- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_LOGIN);
if (!ab)
return;

@@ -2297,6 +2348,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
oldsessionid, sessionid, !rc);
audit_put_tty(tty);
audit_log_end(ab);
+ audit_free_local(context);
}

/**
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 1ba14a7a38f7..fd71c6bac200 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1098,12 +1098,14 @@ static void audit_list_rules(int seq, struct sk_buff_head *q)
/* Log rule additions and removals */
static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
{
+ struct audit_context *context;
struct audit_buffer *ab;

if (!audit_enabled)
return;

- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
if (!ab)
return;
audit_log_session_info(ab);
@@ -1112,6 +1114,7 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re
audit_log_key(ab, rule->filterkey);
audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
audit_log_end(ab);
+ audit_free_local(context);
}

/**
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0e58a3ab56f5..01fdcbf468c0 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -993,12 +993,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags)
context = audit_alloc_context(AUDIT_STATE_BUILD, gfpflags);
if (!context) {
audit_log_lost("out of memory in audit_alloc_local");
- goto out;
+ return NULL;
}
context->serial = audit_serial();
ktime_get_coarse_real_ts64(&context->ctime);
context->local = true;
-out:
return context;
}
EXPORT_SYMBOL(audit_alloc_local);
@@ -1019,6 +1018,13 @@ void audit_free_context(struct audit_context *context)
}
EXPORT_SYMBOL(audit_free_context);

+void audit_free_local(struct audit_context *context)
+{
+ if (context && context->local)
+ audit_free_context(context);
+}
+EXPORT_SYMBOL(audit_free_local);
+
static int audit_log_pid_context(struct audit_context *context, pid_t pid,
kuid_t auid, kuid_t uid,
unsigned int sessionid,
@@ -1036,7 +1042,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (lsmblob_is_set(blob)) {
- if (security_secid_to_secctx(blob, &lsmctx)) {
+ if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1282,7 +1288,8 @@ static void show_special(struct audit_context *context, int *call_panic)
struct lsmblob blob;

lsmblob_init(&blob, osid);
- if (security_secid_to_secctx(&blob, &lsmcxt)) {
+ if (security_secid_to_secctx(&blob, &lsmcxt,
+ LSMBLOB_FIRST)) {
audit_log_format(ab, " osid=%u", osid);
*call_panic = 1;
} else {
@@ -1439,7 +1446,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
struct lsmcontext lsmctx;

lsmblob_init(&blob, n->osid);
- if (security_secid_to_secctx(&blob, &lsmctx)) {
+ if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
audit_log_format(ab, " osid=%u", n->osid);
if (call_panic)
*call_panic = 2;
@@ -2637,10 +2644,12 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
enum audit_nfcfgop op, gfp_t gfp)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char comm[sizeof(current->comm)];

- ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, gfp, AUDIT_NETFILTER_CFG);
if (!ab)
return;
audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
@@ -2651,6 +2660,7 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
audit_log_format(ab, " comm=");
audit_log_untrustedstring(ab, get_task_comm(comm, current));
audit_log_end(ab);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(__audit_log_nfcfg);

@@ -2685,6 +2695,7 @@ static void audit_log_task(struct audit_buffer *ab)
*/
void audit_core_dumps(long signr)
{
+ struct audit_context *context;
struct audit_buffer *ab;

if (!audit_enabled)
@@ -2693,12 +2704,14 @@ void audit_core_dumps(long signr)
if (signr == SIGQUIT) /* don't care for those */
return;

- ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_ANOM_ABEND);
if (unlikely(!ab))
return;
audit_log_task(ab);
audit_log_format(ab, " sig=%ld res=1", signr);
audit_log_end(ab);
+ audit_free_local(context);
}

/**
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ae073b642fa7..5c0029a3a595 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -140,7 +140,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
return;

lsmblob_init(&lb, secid);
- err = security_secid_to_secctx(&lb, &context);
+ err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY);
if (err)
return;

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 668b31ecd638..05bdbb942499 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -347,7 +347,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
* security_secid_to_secctx() will know which security module
* to use to create the secctx. */
lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return 0;

@@ -658,7 +658,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
struct lsmblob blob;
struct lsmcontext context;

- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return 0;

diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index b5796a8e5e90..3da3770e9739 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -177,7 +177,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
struct lsmcontext context;

lsmblob_init(&blob, ct->secmark);
- ret = security_secid_to_secctx(&blob, &context);
+ ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY);
if (ret)
return;

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index cffb04baf7b8..9bef0bddf7d6 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -316,7 +316,7 @@ static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
* blob. security_secid_to_secctx() will know which security
* module to use to create the secctx. */
lsmblob_init(&blob, skb->secmark);
- security_secid_to_secctx(&blob, context);
+ security_secid_to_secctx(&blob, context, LSMBLOB_DISPLAY);
}

read_unlock_bh(&skb->sk->sk_callback_lock);
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 289602835b75..245f63f5773a 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -437,7 +437,8 @@ int netlbl_unlhsh_add(struct net *net,
unlhsh_add_return:
rcu_read_unlock();
if (audit_buf != NULL) {
- if (security_secid_to_secctx(lsmblob, &context) == 0) {
+ if (security_secid_to_secctx(lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -492,7 +493,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
if (dev != NULL)
dev_put(dev);
if (entry != NULL &&
- security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -552,7 +554,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
if (dev != NULL)
dev_put(dev);
if (entry != NULL &&
- security_secid_to_secctx(&entry->lsmblob, &context) == 0) {
+ security_secid_to_secctx(&entry->lsmblob, &context,
+ LSMBLOB_FIRST) == 0) {
audit_log_format(audit_buf, " sec_obj=%s",
context.context);
security_release_secctx(&context);
@@ -738,11 +741,10 @@ static void netlbl_unlabel_acceptflg_set(u8 value,
netlabel_unlabel_acceptflg = value;
audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
audit_info);
- if (audit_buf != NULL) {
+ if (audit_buf != NULL)
audit_log_format(audit_buf,
" unlbl_accept=%u old=%u", value, old_val);
- audit_log_end(audit_buf);
- }
+ audit_log_end(audit_buf);
}

/**
@@ -1122,7 +1124,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
lsmb = (struct lsmblob *)&addr6->lsmblob;
}

- ret_val = security_secid_to_secctx(lsmb, &context);
+ ret_val = security_secid_to_secctx(lsmb, &context, LSMBLOB_FIRST);
if (ret_val != 0)
goto list_cb_failure;
ret_val = nla_put(cb_arg->skb,
@@ -1528,14 +1530,11 @@ int __init netlbl_unlabel_defconf(void)
int ret_val;
struct netlbl_dom_map *entry;
struct netlbl_audit audit_info;
- struct lsmblob blob;

/* Only the kernel is allowed to call this function and the only time
* it is called is at bootup before the audit subsystem is reporting
* messages so don't worry to much about these values. */
- security_task_getsecid_subj(current, &blob);
- /* scaffolding until audit_info.secid is converted */
- audit_info.secid = blob.secid[0];
+ security_task_getsecid_subj(current, &audit_info.lsmdata);
audit_info.loginuid = GLOBAL_ROOT_UID;
audit_info.sessionid = 0;

diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 951ba0639d20..9c43c3cb2088 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -85,7 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
{
struct audit_buffer *audit_buf;
struct lsmcontext context;
- struct lsmblob blob;

if (audit_enabled == AUDIT_OFF)
return NULL;
@@ -98,11 +97,14 @@ struct audit_buffer *netlbl_audit_start_common(int type,
from_kuid(&init_user_ns, audit_info->loginuid),
audit_info->sessionid);

- lsmblob_init(&blob, audit_info->secid);
- if (audit_info->secid != 0 &&
- security_secid_to_secctx(&blob, &context) == 0) {
- audit_log_format(audit_buf, " subj=%s", context.context);
- security_release_secctx(&context);
+ if (lsmblob_is_set(&audit_info->lsmdata)) {
+ if (!lsm_multiple_contexts() &&
+ security_secid_to_secctx(&audit_info->lsmdata, &context,
+ LSMBLOB_FIRST) == 0) {
+ audit_log_format(audit_buf, " subj=%s",
+ context.context);
+ security_release_secctx(&context);
+ }
}

return audit_buf;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index aa31f7bf79ee..e5b15ad41df7 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -32,11 +32,7 @@
*/
static inline void netlbl_netlink_auditinfo(struct netlbl_audit *audit_info)
{
- struct lsmblob blob;
-
- security_task_getsecid_subj(current, &blob);
- /* scaffolding until secid is converted */
- audit_info->secid = blob.secid[0];
+ security_task_getsecid_subj(current, &audit_info->lsmdata);
audit_info->loginuid = audit_get_loginuid(current);
audit_info->sessionid = audit_get_sessionid(current);
}
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 827d84255021..2152e319951d 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4178,30 +4178,34 @@ static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp,

void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;

- audit_buf = xfrm_audit_start("SPD-add");
+ audit_buf = xfrm_audit_start("SPD-add", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
xfrm_audit_common_policyinfo(xp, audit_buf);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);

void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;

- audit_buf = xfrm_audit_start("SPD-delete");
+ audit_buf = xfrm_audit_start("SPD-delete", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
xfrm_audit_common_policyinfo(xp, audit_buf);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete);
#endif
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index a2f4001221d1..4d174f42eb60 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2796,29 +2796,33 @@ static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family,

void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;

- audit_buf = xfrm_audit_start("SAD-add");
+ audit_buf = xfrm_audit_start("SAD-add", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
xfrm_audit_helper_sainfo(x, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_add);

void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid)
{
+ struct audit_context *context;
struct audit_buffer *audit_buf;

- audit_buf = xfrm_audit_start("SAD-delete");
+ audit_buf = xfrm_audit_start("SAD-delete", &context);
if (audit_buf == NULL)
return;
xfrm_audit_helper_usrinfo(task_valid, audit_buf);
xfrm_audit_helper_sainfo(x, audit_buf);
audit_log_format(audit_buf, " res=%u", result);
audit_log_end(audit_buf);
+ audit_free_local(context);
}
EXPORT_SYMBOL_GPL(xfrm_audit_state_delete);

@@ -2828,7 +2832,7 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
struct audit_buffer *audit_buf;
u32 spi;

- audit_buf = xfrm_audit_start("SA-replay-overflow");
+ audit_buf = xfrm_audit_start("SA-replay-overflow", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2846,7 +2850,7 @@ void xfrm_audit_state_replay(struct xfrm_state *x,
struct audit_buffer *audit_buf;
u32 spi;

- audit_buf = xfrm_audit_start("SA-replayed-pkt");
+ audit_buf = xfrm_audit_start("SA-replayed-pkt", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
@@ -2861,7 +2865,7 @@ void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family)
{
struct audit_buffer *audit_buf;

- audit_buf = xfrm_audit_start("SA-notfound");
+ audit_buf = xfrm_audit_start("SA-notfound", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2875,7 +2879,7 @@ void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
struct audit_buffer *audit_buf;
u32 spi;

- audit_buf = xfrm_audit_start("SA-notfound");
+ audit_buf = xfrm_audit_start("SA-notfound", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, family, audit_buf);
@@ -2893,7 +2897,7 @@ void xfrm_audit_state_icvfail(struct xfrm_state *x,
__be32 net_spi;
__be32 net_seq;

- audit_buf = xfrm_audit_start("SA-icv-failure");
+ audit_buf = xfrm_audit_start("SA-icv-failure", NULL);
if (audit_buf == NULL)
return;
xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 691f68d478f1..3481990a25a6 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -342,6 +342,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char *hash;
const char *algo_name = hash_algo_name[iint->ima_hash->algo];
@@ -358,8 +359,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]);
hash[i * 2] = '\0';

- ab = audit_log_start(audit_context(), GFP_KERNEL,
- AUDIT_INTEGRITY_RULE);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
if (!ab)
goto out;

@@ -369,6 +370,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,

audit_log_task_info(ab);
audit_log_end(ab);
+ audit_free_local(context);

iint->flags |= IMA_AUDITED;
out:
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 29220056207f..c3b313886e15 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -38,13 +38,15 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
const char *cause, int result, int audit_info,
int errno)
{
+ struct audit_context *context;
struct audit_buffer *ab;
char name[TASK_COMM_LEN];

if (!integrity_audit_info && audit_info == 1) /* Skip info messages */
return;

- ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno);
+ context = audit_alloc_for_lsm(GFP_KERNEL);
+ ab = audit_log_start(context, GFP_KERNEL, audit_msgno);
audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
task_pid_nr(current),
from_kuid(&init_user_ns, current_uid()),
@@ -64,4 +66,5 @@ void integrity_audit_message(int audit_msgno, struct inode *inode,
}
audit_log_format(ab, " res=%d errno=%d", !result, errno);
audit_log_end(ab);
+ audit_free_local(context);
}
diff --git a/security/security.c b/security/security.c
index cb359e185d1a..5d7fd982f84a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2309,7 +2309,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
hlist_for_each_entry(hp, &security_hook_heads.setprocattr,
list) {
rc = hp->hook.setprocattr(name, value, size);
- if (rc < 0)
+ if (rc < 0 && rc != -EINVAL)
return rc;
}

@@ -2354,13 +2354,31 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);

-int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp,
+ int ilsm)
{
struct security_hook_list *hp;
- int ilsm = lsm_task_ilsm(current);

memset(cp, 0, sizeof(*cp));

+ /*
+ * ilsm either is the slot number use for formatting
+ * or an instruction on which relative slot to use.
+ */
+ if (ilsm == LSMBLOB_DISPLAY)
+ ilsm = lsm_task_ilsm(current);
+ else if (ilsm == LSMBLOB_FIRST)
+ ilsm = LSMBLOB_INVALID;
+ else if (ilsm < 0) {
+ WARN_ONCE(true,
+ "LSM: %s unknown interface LSM\n", __func__);
+ ilsm = LSMBLOB_INVALID;
+ } else if (ilsm >= lsm_slot) {
+ WARN_ONCE(true,
+ "LSM: %s invalid interface LSM\n", __func__);
+ ilsm = LSMBLOB_INVALID;
+ }
+
hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
@@ -2390,7 +2408,7 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
return hp->hook.secctx_to_secid(secdata, seclen,
&blob->secid[hp->lsmid->slot]);
}
- return 0;
+ return -EOPNOTSUPP;
}
EXPORT_SYMBOL(security_secctx_to_secid);

@@ -2884,23 +2902,17 @@ int security_key_getsecurity(struct key *key, char **_buffer)
int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
{
struct security_hook_list *hp;
- bool one_is_good = false;
- int rc = 0;
- int trc;
+ int ilsm = lsm_task_ilsm(current);

hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
continue;
- trc = hp->hook.audit_rule_init(field, op, rulestr,
- &lsmrule[hp->lsmid->slot]);
- if (trc == 0)
- one_is_good = true;
- else
- rc = trc;
+ if (ilsm != LSMBLOB_INVALID && ilsm != hp->lsmid->slot)
+ continue;
+ return hp->hook.audit_rule_init(field, op, rulestr,
+ &lsmrule[hp->lsmid->slot]);
}
- if (one_is_good)
- return 0;
- return rc;
+ return 0;
}

int security_audit_rule_known(struct audit_krule *krule)
@@ -2932,6 +2944,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
continue;
if (lsmrule[hp->lsmid->slot] == NULL)
continue;
+ if (lsmrule[hp->lsmid->slot] == NULL)
+ continue;
rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
field, op,
&lsmrule[hp->lsmid->slot]);
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 9cda52f2ec31..2f0f412fc403 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -185,7 +185,8 @@ static void smk_netlabel_audit_set(struct netlbl_audit *nap)

nap->loginuid = audit_get_loginuid(current);
nap->sessionid = audit_get_sessionid(current);
- nap->secid = skp->smk_secid;
+ lsmblob_init(&nap->lsmdata, 0);
+ nap->lsmdata.secid[smack_lsmid.slot] = skp->smk_secid;
}

/*
--
2.31.1

2021-07-22 01:15:43

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 23/25] Audit: Add record for multiple object LSM attributes

Create a new audit record type to contain the object information
when there are multiple security modules that may require such data.
This record is linked with the same timestamp and serial number.

An example of the MAC_OBJ_CONTEXTS (1421) record is:

type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux="unconfined_u:object_r:user_home_t:s0"

Not all security modules that can provide object information
do so in all cases. It is possible that a security module won't
apply an object attribute in all cases.

Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
To: Paul Moore <[email protected]>
---
include/linux/audit.h | 7 ++++
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 54 ++++++++++++++++++++++++++++
kernel/audit.h | 4 +--
kernel/auditsc.c | 73 +++++++-------------------------------
5 files changed, 76 insertions(+), 63 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 85eb87f6f92d..6bf0c86fcbc9 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -187,6 +187,8 @@ extern void audit_log_path_denied(int type,
extern void audit_log_lost(const char *message);

extern int audit_log_task_context(struct audit_buffer *ab);
+extern int audit_log_object_context(struct audit_buffer *ab,
+ struct lsmblob *blob);
extern void audit_log_task_info(struct audit_buffer *ab);

extern int audit_update_lsm_rules(void);
@@ -250,6 +252,11 @@ static inline int audit_log_task_context(struct audit_buffer *ab)
{
return 0;
}
+static inline int audit_log_object_context(struct audit_buffer *ab,
+ struct lsmblob *blob)
+{
+ return 0;
+}
static inline void audit_log_task_info(struct audit_buffer *ab)
{ }

diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 4432a8bed8e0..4efed1abcd54 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -140,6 +140,7 @@
#define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */
#define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */
#define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM contexts */
+#define AUDIT_MAC_OBJ_CONTEXTS 1421 /* Multiple LSM object contexts */

#define AUDIT_FIRST_KERN_ANOM_MSG 1700
#define AUDIT_LAST_KERN_ANOM_MSG 1799
diff --git a/kernel/audit.c b/kernel/audit.c
index cba63789a164..c500b303e39f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2204,6 +2204,60 @@ int audit_log_task_context(struct audit_buffer *ab)
}
EXPORT_SYMBOL(audit_log_task_context);

+int audit_log_object_context(struct audit_buffer *ab,
+ struct lsmblob *blob)
+{
+ int i;
+ int error;
+ bool sep = false;
+ struct lsmcontext lsmdata;
+ struct audit_buffer *lsmab = NULL;
+ struct audit_context *context = NULL;
+
+ /*
+ * If there is more than one security module that has a
+ * object "context" it's necessary to put the object data
+ * into a separate record to maintain compatibility.
+ */
+ if (lsm_multiple_contexts()) {
+ audit_log_format(ab, " obj=?");
+ context = ab->ctx;
+ if (context)
+ lsmab = audit_log_start(context, GFP_KERNEL,
+ AUDIT_MAC_OBJ_CONTEXTS);
+ WARN_ONCE(!context, "Context not set for object\n");
+ }
+
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (blob->secid[i] == 0)
+ continue;
+ error = security_secid_to_secctx(blob, &lsmdata, i);
+ if (error && error != -EINVAL) {
+ audit_panic("error in audit_log_object_context");
+ return error;
+ }
+
+ if (context) {
+ audit_log_format(lsmab, "%sobj_%s=\"%s\"",
+ sep ? " " : "",
+ lsm_slot_to_name(i),
+ lsmdata.context);
+ sep = true;
+ } else
+ audit_log_format(ab, " obj=%s", lsmdata.context);
+
+ security_release_secctx(&lsmdata);
+ if (!context)
+ break;
+ }
+
+ if (context)
+ audit_log_end(lsmab);
+
+ return 0;
+}
+EXPORT_SYMBOL(audit_log_object_context);
+
void audit_log_d_path_exe(struct audit_buffer *ab,
struct mm_struct *mm)
{
diff --git a/kernel/audit.h b/kernel/audit.h
index ddc1a69edc79..d62f3cb09278 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -78,7 +78,7 @@ struct audit_names {
kuid_t uid;
kgid_t gid;
dev_t rdev;
- u32 osid;
+ struct lsmblob oblob;
struct audit_cap_data fcap;
unsigned int fcap_ver;
unsigned char type; /* record type */
@@ -153,7 +153,7 @@ struct audit_context {
kuid_t uid;
kgid_t gid;
umode_t mode;
- u32 osid;
+ struct lsmblob oblob;
int has_perm;
uid_t perm_uid;
gid_t perm_gid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 01fdcbf468c0..5261a69a050a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -691,14 +691,6 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_isset) {
/* Find files that match */
if (name) {
- /*
- * lsmblob_init sets all values in the
- * lsmblob to sid. This is temporary
- * until name->osid is converted to a
- * lsmblob, which happens later in
- * this patch set.
- */
- lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
&blob,
f->type,
@@ -706,7 +698,6 @@ static int audit_filter_rules(struct task_struct *tsk,
f->lsm_rules);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
- lsmblob_init(&blob, name->osid);
if (security_audit_rule_match(
&blob,
f->type,
@@ -720,8 +711,7 @@ static int audit_filter_rules(struct task_struct *tsk,
/* Find ipc objects that match */
if (!ctx || ctx->type != AUDIT_IPC)
break;
- lsmblob_init(&blob, ctx->ipc.osid);
- if (security_audit_rule_match(&blob,
+ if (security_audit_rule_match(&ctx->ipc.oblob,
f->type, f->op,
f->lsm_rules))
++result;
@@ -1031,7 +1021,6 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
struct lsmblob *blob, char *comm)
{
struct audit_buffer *ab;
- struct lsmcontext lsmctx;
int rc = 0;

ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
@@ -1041,15 +1030,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
- if (lsmblob_is_set(blob)) {
- if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
- audit_log_format(ab, " obj=(none)");
- rc = 1;
- } else {
- audit_log_format(ab, " obj=%s", lsmctx.context);
- security_release_secctx(&lsmctx);
- }
- }
+ if (lsmblob_is_set(blob))
+ rc = audit_log_object_context(ab, blob);
audit_log_format(ab, " ocomm=");
audit_log_untrustedstring(ab, comm);
audit_log_end(ab);
@@ -1277,26 +1259,15 @@ static void show_special(struct audit_context *context, int *call_panic)
context->socketcall.args[i]);
break; }
case AUDIT_IPC: {
- u32 osid = context->ipc.osid;
+ struct lsmblob *oblob = &context->ipc.oblob;

audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
from_kuid(&init_user_ns, context->ipc.uid),
from_kgid(&init_user_ns, context->ipc.gid),
context->ipc.mode);
- if (osid) {
- struct lsmcontext lsmcxt;
- struct lsmblob blob;
-
- lsmblob_init(&blob, osid);
- if (security_secid_to_secctx(&blob, &lsmcxt,
- LSMBLOB_FIRST)) {
- audit_log_format(ab, " osid=%u", osid);
- *call_panic = 1;
- } else {
- audit_log_format(ab, " obj=%s", lsmcxt.context);
- security_release_secctx(&lsmcxt);
- }
- }
+ if (lsmblob_is_set(oblob) &&
+ audit_log_object_context(ab, oblob))
+ *call_panic = 1;
if (context->ipc.has_perm) {
audit_log_end(ab);
ab = audit_log_start(context, GFP_KERNEL,
@@ -1441,20 +1412,9 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
from_kgid(&init_user_ns, n->gid),
MAJOR(n->rdev),
MINOR(n->rdev));
- if (n->osid != 0) {
- struct lsmblob blob;
- struct lsmcontext lsmctx;
-
- lsmblob_init(&blob, n->osid);
- if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
- audit_log_format(ab, " osid=%u", n->osid);
- if (call_panic)
- *call_panic = 2;
- } else {
- audit_log_format(ab, " obj=%s", lsmctx.context);
- security_release_secctx(&lsmctx);
- }
- }
+ if (lsmblob_is_set(&n->oblob) &&
+ audit_log_object_context(ab, &n->oblob) && call_panic)
+ *call_panic = 2;

/* log the audit_names record type */
switch (n->type) {
@@ -2001,17 +1961,13 @@ static void audit_copy_inode(struct audit_names *name,
const struct dentry *dentry,
struct inode *inode, unsigned int flags)
{
- struct lsmblob blob;
-
name->ino = inode->i_ino;
name->dev = inode->i_sb->s_dev;
name->mode = inode->i_mode;
name->uid = inode->i_uid;
name->gid = inode->i_gid;
name->rdev = inode->i_rdev;
- security_inode_getsecid(inode, &blob);
- /* scaffolding until osid is updated */
- name->osid = blob.secid[0];
+ security_inode_getsecid(inode, &name->oblob);
if (flags & AUDIT_INODE_NOEVAL) {
name->fcap_ver = -1;
return;
@@ -2358,17 +2314,12 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
{
struct audit_context *context = audit_context();
- struct lsmblob blob;

context->ipc.uid = ipcp->uid;
context->ipc.gid = ipcp->gid;
context->ipc.mode = ipcp->mode;
context->ipc.has_perm = 0;
- security_ipc_getsecid(ipcp, &blob);
- /* context->ipc.osid will be changed to a lsmblob later in
- * the patch series. This will allow auditing of all the object
- * labels associated with the ipc object. */
- context->ipc.osid = lsmblob_value(&blob);
+ security_ipc_getsecid(ipcp, &context->ipc.oblob);
context->type = AUDIT_IPC;
}

--
2.31.1

2021-07-22 01:16:50

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 24/25] LSM: Add /proc attr entry for full LSM context

Add an entry /proc/.../attr/context which displays the full
process security "context" in compound format:
lsm1\0value\0lsm2\0value\0...
This entry is not writable.

A security module may decide that its policy does not allow
this information to be displayed. In this case none of the
information will be displayed.

Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
Documentation/ABI/testing/procfs-attr-context | 14 ++++
Documentation/security/lsm.rst | 14 ++++
fs/proc/base.c | 1 +
include/linux/lsm_hooks.h | 6 ++
security/apparmor/include/procattr.h | 2 +-
security/apparmor/lsm.c | 8 +-
security/apparmor/procattr.c | 22 +++---
security/security.c | 79 +++++++++++++++++++
security/selinux/hooks.c | 2 +-
security/smack/smack_lsm.c | 2 +-
10 files changed, 135 insertions(+), 15 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-context

diff --git a/Documentation/ABI/testing/procfs-attr-context b/Documentation/ABI/testing/procfs-attr-context
new file mode 100644
index 000000000000..40da1c397c30
--- /dev/null
+++ b/Documentation/ABI/testing/procfs-attr-context
@@ -0,0 +1,14 @@
+What: /proc/*/attr/context
+Contact: [email protected],
+Description: The current security information used by all Linux
+ security module (LSMs) that are active on the system.
+ The details of permissions required to read from
+ this interface and hence obtain the security state
+ of the task identified is dependent on the LSMs that
+ are active on the system.
+ A process cannot write to this interface.
+ The data provided by this interface will have the form:
+ lsm_name\0lsm_data\0[lsm_name\0lsm_data\0]...
+ where lsm_name is the name of the LSM and the following
+ lsm_data is the process data for that LSM.
+Users: LSM user-space
diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index b77b4a540391..070225ae6ceb 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -143,3 +143,17 @@ separated list of the active security modules.
The file ``/proc/pid/attr/interface_lsm`` contains the name of the security
module for which the ``/proc/pid/attr/current`` interface will
apply. This interface can be written to.
+
+The infrastructure does provide an interface for the special
+case where multiple security modules provide a process context.
+This is provided in compound context format.
+
+- `lsm\0value\0lsm\0value\0`
+
+The `lsm` and `value` fields are NUL-terminated bytestrings.
+Each field may contain whitespace or non-printable characters.
+The NUL bytes are included in the size of a compound context.
+The context ``Bell\0Secret\0Biba\0Loose\0`` has a size of 23.
+
+The file ``/proc/pid/attr/context`` provides the security
+context of the identified process.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index f80ed1c40053..387627fd8313 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2821,6 +2821,7 @@ static const struct pid_entry attr_dir_stuff[] = {
ATTR(NULL, "keycreate", 0666),
ATTR(NULL, "sockcreate", 0666),
ATTR(NULL, "interface_lsm", 0666),
+ ATTR(NULL, "context", 0444),
#ifdef CONFIG_SECURITY_SMACK
DIR("smack", 0555,
proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index d2c4bc94d47f..f6ffe8b069e2 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1397,6 +1397,12 @@
* @pages contains the number of pages.
* Return 0 if permission is granted.
*
+ * @getprocattr:
+ * Provide the named process attribute for display in special files in
+ * the /proc/.../attr directory. Attribute naming and the data displayed
+ * is at the discretion of the security modules. The exception is the
+ * "context" attribute, which will contain the security context of the
+ * task as a nul terminated text string without trailing whitespace.
* @ismaclabel:
* Check if the extended attribute specified by @name
* represents a MAC label. Returns 1 if name is a MAC
diff --git a/security/apparmor/include/procattr.h b/security/apparmor/include/procattr.h
index 31689437e0e1..03dbfdb2f2c0 100644
--- a/security/apparmor/include/procattr.h
+++ b/security/apparmor/include/procattr.h
@@ -11,7 +11,7 @@
#ifndef __AA_PROCATTR_H
#define __AA_PROCATTR_H

-int aa_getprocattr(struct aa_label *label, char **string);
+int aa_getprocattr(struct aa_label *label, char **string, bool newline);
int aa_setprocattr_changehat(char *args, size_t size, int flags);

#endif /* __AA_PROCATTR_H */
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4237536106aa..65a004597e53 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -602,6 +602,7 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
const struct cred *cred = get_task_cred(task);
struct aa_task_ctx *ctx = task_ctx(current);
struct aa_label *label = NULL;
+ bool newline = true;

if (strcmp(name, "current") == 0)
label = aa_get_newest_label(cred_label(cred));
@@ -609,11 +610,14 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
label = aa_get_newest_label(ctx->previous);
else if (strcmp(name, "exec") == 0 && ctx->onexec)
label = aa_get_newest_label(ctx->onexec);
- else
+ else if (strcmp(name, "context") == 0) {
+ label = aa_get_newest_label(cred_label(cred));
+ newline = false;
+ } else
error = -EINVAL;

if (label)
- error = aa_getprocattr(label, value);
+ error = aa_getprocattr(label, value, newline);

aa_put_label(label);
put_cred(cred);
diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c
index c929bf4a3df1..be3b083d9b74 100644
--- a/security/apparmor/procattr.c
+++ b/security/apparmor/procattr.c
@@ -20,6 +20,7 @@
* aa_getprocattr - Return the profile information for @profile
* @profile: the profile to print profile info about (NOT NULL)
* @string: Returns - string containing the profile info (NOT NULL)
+ * @newline: Should a newline be added to @string.
*
* Returns: length of @string on success else error on failure
*
@@ -30,20 +31,21 @@
*
* Returns: size of string placed in @string else error code on failure
*/
-int aa_getprocattr(struct aa_label *label, char **string)
+int aa_getprocattr(struct aa_label *label, char **string, bool newline)
{
struct aa_ns *ns = labels_ns(label);
struct aa_ns *current_ns = aa_get_current_ns();
+ int flags = FLAG_VIEW_SUBNS | FLAG_HIDDEN_UNCONFINED;
int len;

if (!aa_ns_visible(current_ns, ns, true)) {
aa_put_ns(current_ns);
return -EACCES;
}
+ if (newline)
+ flags |= FLAG_SHOW_MODE;

- len = aa_label_snxprint(NULL, 0, current_ns, label,
- FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
- FLAG_HIDDEN_UNCONFINED);
+ len = aa_label_snxprint(NULL, 0, current_ns, label, flags);
AA_BUG(len < 0);

*string = kmalloc(len + 2, GFP_KERNEL);
@@ -52,19 +54,19 @@ int aa_getprocattr(struct aa_label *label, char **string)
return -ENOMEM;
}

- len = aa_label_snxprint(*string, len + 2, current_ns, label,
- FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
- FLAG_HIDDEN_UNCONFINED);
+ len = aa_label_snxprint(*string, len + 2, current_ns, label, flags);
if (len < 0) {
aa_put_ns(current_ns);
return len;
}

- (*string)[len] = '\n';
- (*string)[len + 1] = 0;
+ if (newline) {
+ (*string)[len] = '\n';
+ (*string)[++len] = 0;
+ }

aa_put_ns(current_ns);
- return len + 1;
+ return len;
}

/**
diff --git a/security/security.c b/security/security.c
index 5d7fd982f84a..4572da4e27f7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -801,6 +801,57 @@ static int lsm_superblock_alloc(struct super_block *sb)
return 0;
}

+/**
+ * append_ctx - append a lsm/context pair to a compound context
+ * @ctx: the existing compound context
+ * @ctxlen: size of the old context, including terminating nul byte
+ * @lsm: new lsm name, nul terminated
+ * @new: new context, possibly nul terminated
+ * @newlen: maximum size of @new
+ *
+ * replace @ctx with a new compound context, appending @newlsm and @new
+ * to @ctx. On exit the new data replaces the old, which is freed.
+ * @ctxlen is set to the new size, which includes a trailing nul byte.
+ *
+ * Returns 0 on success, -ENOMEM if no memory is available.
+ */
+static int append_ctx(char **ctx, int *ctxlen, const char *lsm, char *new,
+ int newlen)
+{
+ char *final;
+ size_t llen;
+ size_t nlen;
+ size_t flen;
+
+ llen = strlen(lsm) + 1;
+ /*
+ * A security module may or may not provide a trailing nul on
+ * when returning a security context. There is no definition
+ * of which it should be, and there are modules that do it
+ * each way.
+ */
+ nlen = strnlen(new, newlen);
+
+ flen = *ctxlen + llen + nlen + 1;
+ final = kzalloc(flen, GFP_KERNEL);
+
+ if (final == NULL)
+ return -ENOMEM;
+
+ if (*ctxlen)
+ memcpy(final, *ctx, *ctxlen);
+
+ memcpy(final + *ctxlen, lsm, llen);
+ memcpy(final + *ctxlen + llen, new, nlen);
+
+ kfree(*ctx);
+
+ *ctx = final;
+ *ctxlen = flen;
+
+ return 0;
+}
+
/*
* The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
* can be accessed with:
@@ -2234,6 +2285,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
char **value)
{
struct security_hook_list *hp;
+ char *final = NULL;
+ char *cp;
+ int rc = 0;
+ int finallen = 0;
int ilsm = lsm_task_ilsm(current);
int slot = 0;

@@ -2261,6 +2316,30 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
return -ENOMEM;
}

+ if (!strcmp(name, "context")) {
+ hlist_for_each_entry(hp, &security_hook_heads.getprocattr,
+ list) {
+ rc = hp->hook.getprocattr(p, "context", &cp);
+ if (rc == -EINVAL)
+ continue;
+ if (rc < 0) {
+ kfree(final);
+ return rc;
+ }
+ rc = append_ctx(&final, &finallen, hp->lsmid->lsm,
+ cp, rc);
+ kfree(cp);
+ if (rc < 0) {
+ kfree(final);
+ return rc;
+ }
+ }
+ if (final == NULL)
+ return -EINVAL;
+ *value = final;
+ return finallen;
+ }
+
hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
continue;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 12ae311b7275..046570556e5a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6458,7 +6458,7 @@ static int selinux_getprocattr(struct task_struct *p,
goto bad;
}

- if (!strcmp(name, "current"))
+ if (!strcmp(name, "current") || !strcmp(name, "context"))
sid = __tsec->sid;
else if (!strcmp(name, "prev"))
sid = __tsec->osid;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e65497a5c095..1618d7d6154b 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3477,7 +3477,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
char *cp;
int slen;

- if (strcmp(name, "current") != 0)
+ if (strcmp(name, "current") != 0 && strcmp(name, "context") != 0)
return -EINVAL;

cp = kstrdup(skp->smk_known, GFP_KERNEL);
--
2.31.1

2021-07-22 01:19:57

by Casey Schaufler

[permalink] [raw]
Subject: [PATCH v28 25/25] AppArmor: Remove the exclusive flag

With the inclusion of the interface LSM process attribute
mechanism AppArmor no longer needs to be treated as an
"exclusive" security module. Remove the flag that indicates
it is exclusive. Remove the stub getpeersec_dgram AppArmor
hook as it has no effect in the single LSM case and
interferes in the multiple LSM case.

Acked-by: Stephen Smalley <[email protected]>
Acked-by: John Johansen <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
---
security/apparmor/lsm.c | 20 +-------------------
1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 65a004597e53..15af5a5cb0c0 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1138,22 +1138,6 @@ static int apparmor_socket_getpeersec_stream(struct socket *sock,
return error;
}

-/**
- * apparmor_socket_getpeersec_dgram - get security label of packet
- * @sock: the peer socket
- * @skb: packet data
- * @secid: pointer to where to put the secid of the packet
- *
- * Sets the netlabel socket state on sk from parent
- */
-static int apparmor_socket_getpeersec_dgram(struct socket *sock,
- struct sk_buff *skb, u32 *secid)
-
-{
- /* TODO: requires secid support */
- return -ENOPROTOOPT;
-}
-
/**
* apparmor_sock_graft - Initialize newly created socket
* @sk: child sock
@@ -1257,8 +1241,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
#endif
LSM_HOOK_INIT(socket_getpeersec_stream,
apparmor_socket_getpeersec_stream),
- LSM_HOOK_INIT(socket_getpeersec_dgram,
- apparmor_socket_getpeersec_dgram),
LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
#ifdef CONFIG_NETWORK_SECMARK
LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
@@ -1928,7 +1910,7 @@ static int __init apparmor_init(void)

DEFINE_LSM(apparmor) = {
.name = "apparmor",
- .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
+ .flags = LSM_FLAG_LEGACY_MAJOR,
.enabled = &apparmor_enabled,
.blobs = &apparmor_blob_sizes,
.init = apparmor_init,
--
2.31.1