This patchset provides the changes required for
the AppArmor security module to stack safely with any other.
v32: Rebase to 5.17-rc2
Incorporate additional feedback from v30.
v31: Rebase to 5.16-rc4
Incorporate feedback from Paul Moore on the audit
component changes.
v30: Rebase to 5.16-rc1
Replace the integrity sub-system reuse of the audit
subsystem event matching functions with IMA specific
functions. This is done because audit needs to maintain
information about multiple security modules in audit
rules while IMA to restricts the information to a single
security module.
The binder hooks have been changed and are no longer
called with sufficient information to identify the
interface_lsm. Pass that information in the binder
message, and use that in the compatibility decision.
Refactor the audit changes.
v29: Rebase to 5.15-rc1
Rework the supplimental audit record generation. Attach
a list of supplimental data to the audit_buffer and
generate the auxiliary records as needed on event end.
This should be usable for other auxiliary data, such as
container IDs. There is other ongoing audit work that
will require integration with this.
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 separates the audit rule processing from the
integrity rule processing. They were never really the
same, but void pointers could hide that. The changes
following use the rule pointers differently in audit
and IMA, so keeping the code common is not a good idea.
Patch 02 moves management of the sock security blob
from the individual modules to the infrastructure.
Patches 03-04 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 05 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 06-15 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 15 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 16 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 17-18 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.
Patch 21 adds a parameter to security_secid_to_secctx()
that indicates which of the security modules should be used
to provide the context.
Patches 22-24 provide mechanism to keeping a list of auxiliary
record data in an audit_buffer. The list is read when the
audit record is ended, and supplimental records are created
as needed.
Patch 25 adds a supplimental audit record for subject
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_TASK_CONTEXTS record identifies the security module
with the data: subj_selinux="xyz_t" subj_apparmor="abc".
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor==unconfined
subj_smack=_
Patch 26 adds a supplimental audit record for object
LSM data when there are multiple security modules with such data.
The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction The
with a "obj=?" field to identify the object data.
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_OBJ_CONTEXTS (1421) record is:
type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux=unconfined_u:object_r:user_home_t:s0
Patch 27 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 28 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-5.17-rc2-v32
Casey Schaufler (28):
integrity: disassociate ima_filter_rule from security_audit_rule
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_current_getsecid
LSM: Use lsmblob in security_inode_getsecid
LSM: Use lsmblob in security_cred_getsecid
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
binder: Pass LSM identifier for confirmation
LSM: Extend security_secid_to_secctx to include module selection
Audit: Keep multiple LSM data in audit_names
Audit: Create audit_stamp structure
Audit: Add framework for auxiliary records
Audit: Add record for multiple task security contexts
Audit: Add record for multiple object security contexts
LSM: Add /proc attr entry for full LSM context
AppArmor: Remove the exclusive flag
Documentation/ABI/testing/ima_policy | 8 +-
.../ABI/testing/procfs-attr-lsm_display | 22 +
Documentation/security/lsm.rst | 28 +
drivers/android/binder.c | 47 +-
drivers/android/binder_internal.h | 1 +
fs/ceph/xattr.c | 6 +-
fs/nfs/nfs4proc.c | 8 +-
fs/nfsd/nfs4xdr.c | 20 +-
fs/proc/base.c | 2 +
include/linux/audit.h | 15 +-
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 19 +-
include/linux/security.h | 243 ++++++-
include/net/netlabel.h | 8 +-
include/net/scm.h | 15 +-
include/uapi/linux/audit.h | 2 +
kernel/audit.c | 250 +++++--
kernel/audit.h | 17 +-
kernel/auditfilter.c | 29 +-
kernel/auditsc.c | 128 ++--
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 | 101 ++-
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 13 +-
net/netlabel/netlabel_user.h | 6 +-
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 | 26 -
security/integrity/ima/ima_appraise.c | 12 +-
security/integrity/ima/ima_main.c | 63 +-
security/integrity/ima/ima_policy.c | 58 +-
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 | 615 ++++++++++++++++--
security/selinux/hooks.c | 99 +--
security/selinux/include/classmap.h | 3 +-
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 | 4 +-
security/smack/smackfs.c | 10 +-
security/tomoyo/tomoyo.c | 8 +-
security/yama/yama_lsm.c | 7 +-
66 files changed, 1746 insertions(+), 624 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display
--
2.31.1
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 1ee58c1491ab..388298a15556 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1145,22 +1145,6 @@ 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
@@ -1264,8 +1248,6 @@ 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),
@@ -1919,7 +1901,7 @@ 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
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.
security_secid_to_secctx() will now return the length value
if the passed lsmcontext pointer is NULL.
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 | 42 +++++++++++--------------
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 | 29 +++++++++++++++--
12 files changed, 99 insertions(+), 127 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 2125b4b795da..b0b0c132a247 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2723,9 +2723,7 @@ 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 = { };
struct list_head sgc_head;
struct list_head pf_head;
const void __user *user_buffer = (const void __user *)
@@ -2985,14 +2983,14 @@ static void binder_transaction(struct binder_proc *proc,
size_t added_size;
security_cred_getsecid(proc->cred, &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 */
@@ -3019,24 +3017,22 @@ 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;
@@ -3080,7 +3076,7 @@ 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)) {
@@ -3435,10 +3431,8 @@ 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 72da145c1aad..79554e5adb4c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -596,7 +596,7 @@ 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);
@@ -1450,7 +1450,7 @@ 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 5aa2ee06c9e4..03824cca058c 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1188,9 +1188,6 @@ 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)
@@ -1438,33 +1435,33 @@ 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 = { };
+
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(struct_size(sig_data, ctx, len), GFP_KERNEL);
+ sig_data = kmalloc(struct_size(sig_data, ctx, 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);
+ memcpy(sig_data->ctx, context.context, context.len);
+ security_release_secctx(&context);
}
- audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
- sig_data, struct_size(sig_data, ctx, len));
+ audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, sig_data,
+ struct_size(sig_data, ctx, context.len));
kfree(sig_data);
break;
+ }
case AUDIT_TTY_GET: {
struct audit_tty_status s;
unsigned int t;
@@ -2147,17 +2144,15 @@ 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_current_getsecid_subj(&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)
@@ -2165,9 +2160,8 @@ int audit_log_task_context(struct audit_buffer *ab)
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 1626d8aabe83..7858da40a767 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1121,9 +1121,7 @@ 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);
@@ -1134,13 +1132,12 @@ 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=");
@@ -1353,7 +1350,6 @@ 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;
@@ -1378,17 +1374,15 @@ 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);
}
}
@@ -1543,20 +1537,17 @@ 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 70ca4510ea35..ad5be7707bca 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 212e12b53adb..9626e2b0ef12 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;
}
@@ -656,15 +654,11 @@ static inline size_t ctnetlink_acct_size(const struct nf_conn *ct)
static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
{
#ifdef CONFIG_NF_CONNTRACK_SECMARK
- int len, ret;
+ int len;
struct lsmblob blob;
- /* 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)
+ len = security_secid_to_secctx(&blob, NULL);
+ if (len <= 0)
return 0;
return nla_total_size(0) /* CTA_SECCTX */
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 3b6ba86783f6..36338660df3c 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -176,19 +176,16 @@ 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 d986bae1587b..625cd787ffc1 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 a8e9ee202245..46706889a6f7 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);
@@ -509,11 +502,9 @@ 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);
@@ -552,8 +543,6 @@ 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);
@@ -578,10 +567,9 @@ 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);
@@ -1104,8 +1092,6 @@ 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,
@@ -1165,15 +1151,13 @@ 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 163cf0ae2429..d56fcb794ff4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2330,18 +2330,41 @@ int security_ismaclabel(const char *name)
}
EXPORT_SYMBOL(security_ismaclabel);
-int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
+/**
+ * security_secid_to_secctx - convert secid to secctx
+ * @blob: set of secids
+ * @cp: lsm context into which result is put
+ *
+ * Translate secid information into a secctx string.
+ * Return a negative value on error.
+ * If cp is NULL return the length of the string.
+ * Otherwise, return 0.
+ */
+int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
struct security_hook_list *hp;
int ilsm = lsm_task_ilsm(current);
+ if (cp)
+ 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) {
+ if (!cp) {
+ int len;
+ int rc;
+ rc = hp->hook.secid_to_secctx(
+ blob->secid[hp->lsmid->slot],
+ NULL, &len);
+ return rc ? rc : len;
+ }
+ 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
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 security 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.
Signed-off-by: Casey Schaufler <[email protected]>
To: Mimi Zohar <[email protected]>
To: [email protected]
---
Documentation/ABI/testing/ima_policy | 8 ++++-
include/linux/security.h | 14 ++++----
security/integrity/ima/ima_policy.c | 51 ++++++++++++++++++++++++----
security/security.c | 35 +++++++++++++++----
4 files changed, 89 insertions(+), 19 deletions(-)
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 839fab811b18..64863e9d87ea 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -26,7 +26,7 @@ Description:
[uid=] [euid=] [gid=] [egid=]
[fowner=] [fgroup=]]
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=] [appraise_algos=] [keyrings=]
base:
@@ -126,6 +126,12 @@ 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
+ module 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/include/linux/security.h b/include/linux/security.h
index 6da0c12c9170..1edbb362ee72 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1977,25 +1977,27 @@ static inline void security_audit_rule_free(struct audit_lsm_rules *lsmrules)
#ifdef CONFIG_IMA_LSM_RULES
#ifdef CONFIG_SECURITY
-int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
-int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
-void ima_filter_rule_free(void *lsmrule);
+int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
+ int lsmslot);
+int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
+ int lsmslot);
+void ima_filter_rule_free(void *lsmrule, int lsmslot);
#else
static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
- void **lsmrule)
+ void **lsmrule, int lsmslot)
{
return 0;
}
static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+ void *lsmrule, int lsmslot)
{
return 0;
}
-static inline void ima_filter_rule_free(void *lsmrule)
+static inline void ima_filter_rule_free(void *lsmrule, int lsmslot)
{ }
#endif /* CONFIG_SECURITY */
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 320ca80aacab..22952efcc0b0 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -90,6 +90,7 @@ struct ima_rule_entry {
bool (*fgroup_op)(kgid_t cred_gid, kgid_t rule_gid); /* gid_eq(), gid_gt(), gid_lt() */
int pcr;
unsigned int allowed_algos; /* bitfield of allowed hash algorithms */
+ int which; /* which LSM rule applies to */
struct {
void *rule; /* LSM file metadata specific */
char *args_p; /* audit value */
@@ -286,6 +287,20 @@ 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;
@@ -357,7 +372,7 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry)
int i;
for (i = 0; i < MAX_LSM_RULES; i++) {
- ima_filter_rule_free(entry->lsm[i].rule);
+ ima_filter_rule_free(entry->lsm[i].rule, entry->which);
kfree(entry->lsm[i].args_p);
}
}
@@ -408,7 +423,8 @@ 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);
+ &nentry->lsm[i].rule,
+ entry->which);
if (!nentry->lsm[i].rule)
pr_warn("rule for LSM \'%s\' is undefined\n",
nentry->lsm[i].args_p);
@@ -624,14 +640,16 @@ 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].rule,
+ rule->which);
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].rule,
+ rule->which);
break;
default:
break;
@@ -1026,7 +1044,7 @@ enum policy_opt {
Opt_fowner_lt, Opt_fgroup_lt,
Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos,
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 = {
@@ -1074,6 +1092,7 @@ 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}
};
@@ -1092,7 +1111,8 @@ 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);
+ &entry->lsm[lsm_rule].rule,
+ entry->which);
if (!entry->lsm[lsm_rule].rule) {
pr_warn("rule for LSM \'%s\' is undefined\n",
entry->lsm[lsm_rule].args_p);
@@ -1781,6 +1801,19 @@ 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 = result;
+ result = 0;
+ break;
case Opt_err:
ima_log_string(ab, "UNKNOWN", p);
result = -EINVAL;
@@ -1817,6 +1850,7 @@ 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;
@@ -1834,6 +1868,9 @@ ssize_t ima_parse_add_rule(char *rule)
INIT_LIST_HEAD(&entry->list);
+ for (i = 0; i < MAX_LSM_RULES; i++)
+ entry->which = ima_rules_lsm;
+
result = ima_parse_rule(p, entry);
if (result) {
ima_free_rule(entry);
@@ -2151,6 +2188,8 @@ 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 >= 0)
+ seq_printf(m, pt(Opt_lsm), lsm_slot_to_name(entry->which));
rcu_read_unlock();
seq_puts(m, "\n");
return 0;
diff --git a/security/security.c b/security/security.c
index 03a0af7e9e81..29fc50322b1f 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2708,19 +2708,42 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op,
* The integrity subsystem uses the same hooks as
* the audit subsystem.
*/
-int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
+int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
+ int lsmslot)
{
- return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+ struct security_hook_list *hp;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list)
+ if (hp->lsmid->slot == lsmslot)
+ return hp->hook.audit_rule_init(field, op, rulestr,
+ lsmrule);
+
+ return 0;
}
-void ima_filter_rule_free(void *lsmrule)
+void ima_filter_rule_free(void *lsmrule, int lsmslot)
{
- 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 (hp->lsmid->slot == lsmslot) {
+ hp->hook.audit_rule_free(lsmrule);
+ return;
+ }
+ }
}
-int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
+ int lsmslot)
{
- return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+ struct security_hook_list *hp;
+
+ hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list)
+ if (hp->lsmid->slot == lsmslot)
+ return hp->hook.audit_rule_match(secid, field, op,
+ lsmrule);
+
+ return 0;
}
#endif /* CONFIG_IMA_LSM_RULES */
--
2.31.1
Add a list for auxiliary record data to the audit_buffer structure.
Add the audit_stamp information to the audit_buffer as there's no
guarantee that there will be an audit_context containing the stamp
associated with the event. At audit_log_end() time create auxiliary
records (none are currently defined) as have been added to the list.
Signed-off-by: Casey Schaufler <[email protected]>
---
kernel/audit.c | 84 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 74 insertions(+), 10 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index f012c3786264..559fb14e0380 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -191,15 +191,25 @@ static struct audit_ctl_mutex {
* should be at least that large. */
#define AUDIT_BUFSIZ 1024
+/* The audit_context_entry contains data required to create an
+ * auxiliary record.
+ */
+struct audit_context_entry {
+ struct list_head list;
+ int type; /* Audit record type */
+};
+
/* The audit_buffer is used when formatting an audit record. The caller
* locks briefly to get the record off the freelist or to allocate the
* buffer, and locks briefly to send the buffer to the netlink layer or
* to place it on a transmit queue. Multiple audit_buffers can be in
* use simultaneously. */
struct audit_buffer {
- struct sk_buff *skb; /* formatted skb ready to send */
- struct audit_context *ctx; /* NULL or associated context */
- gfp_t gfp_mask;
+ struct sk_buff *skb; /* formatted skb ready to send */
+ struct audit_context *ctx; /* NULL or associated context */
+ struct list_head aux_records; /* aux record data */
+ struct audit_stamp stamp; /* event stamp */
+ gfp_t gfp_mask;
};
struct audit_reply {
@@ -1765,6 +1775,7 @@ static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
ab->ctx = ctx;
ab->gfp_mask = gfp_mask;
+ INIT_LIST_HEAD(&ab->aux_records);
return ab;
@@ -1825,7 +1836,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
int type)
{
struct audit_buffer *ab;
- struct audit_stamp stamp;
if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
@@ -1880,14 +1890,14 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
return NULL;
}
- audit_get_stamp(ab->ctx, &stamp);
+ audit_get_stamp(ab->ctx, &ab->stamp);
/* cancel dummy context to enable supporting records */
if (ctx)
ctx->dummy = 0;
audit_log_format(ab, "audit(%llu.%03lu:%u): ",
- (unsigned long long)stamp.ctime.tv_sec,
- stamp.ctime.tv_nsec/1000000,
- stamp.serial);
+ (unsigned long long)ab->stamp.ctime.tv_sec,
+ ab->stamp.ctime.tv_nsec/1000000,
+ ab->stamp.serial);
return ab;
}
@@ -2378,7 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
}
/**
- * audit_log_end - end one audit record
+ * __audit_log_end - end one audit record
* @ab: the audit_buffer
*
* We can not do a netlink send inside an irq context because it blocks (last
@@ -2386,7 +2396,7 @@ int audit_signal_info(int sig, struct task_struct *t)
* queue and a kthread is scheduled to remove them from the queue outside the
* irq context. May be called in any context.
*/
-void audit_log_end(struct audit_buffer *ab)
+void __audit_log_end(struct audit_buffer *ab)
{
struct sk_buff *skb;
struct nlmsghdr *nlh;
@@ -2408,6 +2418,60 @@ void audit_log_end(struct audit_buffer *ab)
wake_up_interruptible(&kauditd_wait);
} else
audit_log_lost("rate limit exceeded");
+}
+
+/**
+ * audit_log_end - end one audit record
+ * @ab: the audit_buffer
+ *
+ * Let __audit_log_end() handle the message while the buffer housekeeping
+ * is done here.
+ * If there are other records that have been deferred for the event
+ * create them here.
+ */
+void audit_log_end(struct audit_buffer *ab)
+{
+ struct audit_context_entry *entry;
+ struct audit_context mcontext;
+ struct audit_context *mctx;
+ struct audit_buffer *mab;
+ struct list_head *l;
+ struct list_head *n;
+
+ if (!ab)
+ return;
+
+ __audit_log_end(ab);
+
+ if (list_empty(&ab->aux_records)) {
+ audit_buffer_free(ab);
+ return;
+ }
+
+ if (ab->ctx == NULL) {
+ mcontext.stamp = ab->stamp;
+ mctx = &mcontext;
+ } else
+ mctx = ab->ctx;
+
+ list_for_each_safe(l, n, &ab->aux_records) {
+ entry = list_entry(l, struct audit_context_entry, list);
+ mab = audit_log_start(mctx, ab->gfp_mask, entry->type);
+ if (!mab) {
+ audit_panic("alloc error in audit_log_end");
+ continue;
+ }
+ switch (entry->type) {
+ /* Don't know of any quite yet. */
+ default:
+ audit_panic("Unknown type in audit_log_end");
+ break;
+ }
+ __audit_log_end(mab);
+ audit_buffer_free(mab);
+ list_del(&entry->list);
+ kfree(entry);
+ }
audit_buffer_free(ab);
}
--
2.31.1
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 62d5f99760aa..bb9c900da6b0 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 46706889a6f7..3aab71ba3841 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,
@@ -496,13 +490,8 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
(dev != NULL ? dev->name : NULL),
addr->s_addr, mask->s_addr);
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);
@@ -543,7 +532,6 @@ 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);
@@ -561,13 +549,8 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
(dev != NULL ? dev->name : NULL),
addr, mask);
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);
@@ -921,14 +904,8 @@ 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);
}
/**
@@ -975,11 +952,8 @@ 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);
}
/**
@@ -1091,8 +1065,7 @@ 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,
@@ -1130,7 +1103,7 @@ 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,
@@ -1144,14 +1117,10 @@ 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,
@@ -1510,7 +1479,7 @@ 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)
@@ -1523,7 +1492,7 @@ 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 3469ffe195e6..7b9cb4d263c0 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7020,7 +7020,7 @@ static int selinux_uring_sqpoll(void)
}
#endif /* CONFIG_IO_URING */
-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 800ab4b4239e..0b8f99703462 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -109,7 +109,7 @@ 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 8e92af7dd284..23a45c9dcf04 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 ef9d0b7b1954..ac79313ea95d 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 __initdata;
+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 d2186e2757be..c6dcafe18912 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -524,7 +524,7 @@ 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 3c1cf65cac87..46d81f638a2b 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3728,11 +3728,12 @@ 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) {
/*
@@ -4751,7 +4752,7 @@ 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 658eab05599e..13c2fa728054 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1143,6 +1143,7 @@ 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;
@@ -1274,10 +1275,13 @@ 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
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/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 +-
9 files changed, 121 insertions(+), 15 deletions(-)
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 e0d41adb38ba..324370d048b1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2829,6 +2829,7 @@ 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 2c2d0ef59a41..51b5acff7f0e 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1396,6 +1396,12 @@
* @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 29181bc8c693..1ee58c1491ab 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 fde332e0ea7d..172550f67fc0 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.
*
* Requires: profile != NULL
*
@@ -28,20 +29,21 @@
*
* 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);
@@ -50,19 +52,19 @@ 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 b694eca9d4f1..b1a95ede7fc2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -802,6 +802,57 @@ 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:
@@ -2210,6 +2261,10 @@ 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;
@@ -2237,6 +2292,30 @@ 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 7b9cb4d263c0..beb0e1cf02b5 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6363,7 +6363,7 @@ 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 46d81f638a2b..d1677339e677 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3485,7 +3485,7 @@ 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
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 | 4 +-
10 files changed, 143 insertions(+), 119 deletions(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 3bf5c658bc44..129d99c6f9ed 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1600,6 +1600,7 @@ 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 4f0eecb67dde..be8976c407f4 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -782,33 +782,15 @@ 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);
}
/**
@@ -817,8 +799,8 @@ 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);
@@ -874,7 +856,7 @@ 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);
@@ -1059,7 +1041,7 @@ 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;
@@ -1072,7 +1054,7 @@ 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;
@@ -1156,7 +1138,7 @@ 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();
@@ -1166,7 +1148,7 @@ 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;
@@ -1183,6 +1165,7 @@ 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 = {
@@ -1219,7 +1202,6 @@ 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),
@@ -1771,7 +1753,7 @@ 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 5208b21c8433..f2d4b20613c8 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
@@ -204,6 +205,7 @@ 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);
}
@@ -340,6 +342,7 @@ 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);
@@ -659,6 +662,28 @@ 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
@@ -2263,12 +2288,21 @@ 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 5b6895e4fc29..dffde40d367e 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4593,7 +4593,7 @@ 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,};
@@ -4650,7 +4650,7 @@ 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 */
@@ -4666,8 +4666,8 @@ 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;
@@ -4682,7 +4682,7 @@ 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;
@@ -4817,7 +4817,7 @@ 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);
@@ -4996,9 +4996,9 @@ 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;
@@ -5030,8 +5030,8 @@ 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,};
@@ -5073,7 +5073,7 @@ 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,};
@@ -5106,7 +5106,7 @@ 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;
@@ -5174,13 +5174,15 @@ 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 ||
@@ -5240,34 +5242,27 @@ 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;
@@ -5281,7 +5276,7 @@ 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;
}
@@ -5291,7 +5286,7 @@ 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)
@@ -5306,7 +5301,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
static int selinux_sctp_assoc_request(struct sctp_association *asoc,
struct sk_buff *skb)
{
- struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
u8 peerlbl_active;
@@ -5457,8 +5452,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
static void selinux_sctp_sk_clone(struct sctp_association *asoc, 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.
@@ -5475,7 +5470,7 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, 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;
@@ -5496,7 +5491,7 @@ 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;
@@ -5513,7 +5508,7 @@ 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))
@@ -5597,7 +5592,7 @@ 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
@@ -5726,7 +5721,7 @@ static unsigned int selinux_ip_output(void *priv, 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;
@@ -5749,7 +5744,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
sk = skb_to_full_sk(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;
@@ -5842,7 +5837,7 @@ static unsigned int selinux_ip_postroute(void *priv,
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
@@ -5871,7 +5866,7 @@ static unsigned int selinux_ip_postroute(void *priv,
} 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;
}
@@ -5920,7 +5915,7 @@ 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;
@@ -6920,6 +6915,7 @@ 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 1321f15799e2..800ab4b4239e 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>
@@ -68,7 +69,7 @@ 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)
@@ -101,7 +102,7 @@ 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)
@@ -236,7 +237,7 @@ 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;
@@ -274,7 +275,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
{
int rc;
struct netlbl_lsm_secattr secattr;
- struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+ struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
struct sockaddr_in addr4;
struct sockaddr_in6 addr6;
@@ -355,7 +356,7 @@ 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;
@@ -373,8 +374,8 @@ 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;
}
@@ -392,7 +393,7 @@ 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)
@@ -507,7 +508,7 @@ 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) &&
@@ -545,7 +546,7 @@ 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
@@ -584,7 +585,7 @@ 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 fc837dcebf96..ef9d0b7b1954 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 14b279cc75c9..d58b50006e79 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1434,7 +1434,7 @@ 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;
@@ -1817,7 +1817,7 @@ 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
@@ -2237,11 +2237,7 @@ 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.
@@ -2255,11 +2251,10 @@ 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
@@ -2268,7 +2263,6 @@ 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) {
@@ -2281,9 +2275,8 @@ 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
@@ -2396,7 +2389,7 @@ 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;
@@ -2428,7 +2421,7 @@ 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.
@@ -2460,7 +2453,7 @@ 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();
@@ -2533,7 +2526,7 @@ 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;
@@ -2621,7 +2614,7 @@ 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;
@@ -2715,7 +2708,7 @@ 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;
@@ -2763,7 +2756,7 @@ 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;
}
@@ -2788,8 +2781,8 @@ 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;
@@ -2852,7 +2845,7 @@ 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);
@@ -3583,9 +3576,9 @@ 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
@@ -3631,8 +3624,8 @@ 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;
@@ -3669,7 +3662,7 @@ 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;
@@ -3881,7 +3874,7 @@ 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);
@@ -3903,7 +3896,7 @@ 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;
@@ -4007,7 +4000,7 @@ 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;
@@ -4056,7 +4049,7 @@ 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:
@@ -4105,7 +4098,7 @@ 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() */
@@ -4125,7 +4118,7 @@ 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;
@@ -4211,7 +4204,7 @@ 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) {
@@ -4747,6 +4740,7 @@ 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),
};
@@ -4857,7 +4851,9 @@ 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 b945c1d3a743..bad71b7e648d 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -26,8 +26,8 @@ static unsigned int smack_ip_output(void *priv,
struct socket_smack *ssp;
struct smack_known *skp;
- if (sk && sk->sk_security) {
- ssp = sk->sk_security;
+ if (sk) {
+ ssp = smack_sock(sk);
skp = ssp->smk_out;
skb->secmark = skp->smk_secid;
}
--
2.31.1
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 3b734ebb7e29..4a256d302d97 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -462,7 +462,7 @@ 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);
@@ -1104,7 +1104,8 @@ static inline void security_cred_getsecid(const struct cred *c, u32 *secid)
*secid = 0;
}
-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 473d17c431f3..e5e41bd4efc3 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -772,14 +772,14 @@ 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);
@@ -795,6 +795,7 @@ EXPORT_SYMBOL(set_security_override);
*/
int set_security_override_from_ctx(struct cred *new, const char *secctx)
{
+ struct lsmblob blob;
u32 secid;
int ret;
@@ -802,7 +803,8 @@ 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 5b2dc867c57d..2178235529eb 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1803,9 +1803,19 @@ 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
Create a new audit record AUDIT_MAC_TASK_CONTEXTS.
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=MAC_TASK_CONTEXTS[1420]
msg=audit(1600880931.832:113)
subj_apparmor=unconfined
subj_smack=_
When an audit event includes a AUDIT_MAC_TASK_CONTEXTS record
the "subj=" field in other records in the event will be "subj=?".
An AUDIT_MAC_TASK_CONTEXTS record is supplied when the system has
multiple security modules that may make access decisions based
on a subject security context.
Signed-off-by: Casey Schaufler <[email protected]>
---
include/linux/security.h | 9 ++++++
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 58 ++++++++++++++++++++++++++++++++------
3 files changed, 60 insertions(+), 8 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 39e113574ba7..280ea8d4778f 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -231,6 +231,15 @@ 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);
+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+ return lsm_slot_to_name(1) != NULL;
+#else
+ return false;
+#endif
+}
+
/**
* lsmblob_value - find the first non-zero value in an lsmblob structure.
* @blob: Pointer to the data
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 8eda133ca4c1..af0aaccfaf57 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -143,6 +143,7 @@
#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 task 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 559fb14e0380..e8744e80ef21 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -197,6 +197,9 @@ static struct audit_ctl_mutex {
struct audit_context_entry {
struct list_head list;
int type; /* Audit record type */
+ union {
+ struct lsmblob lsm_subjs;
+ };
};
/* The audit_buffer is used when formatting an audit record. The caller
@@ -2163,16 +2166,31 @@ int audit_log_task_context(struct audit_buffer *ab)
if (!lsmblob_is_set(&blob))
return 0;
- error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
+ if (!lsm_multiple_contexts()) {
+ error = security_secid_to_secctx(&blob, &context,
+ LSMBLOB_FIRST);
+ if (error) {
+ if (error != -EINVAL)
+ goto error_path;
+ return 0;
+ }
- if (error) {
- if (error != -EINVAL)
+ audit_log_format(ab, " subj=%s", context.context);
+ security_release_secctx(&context);
+ } else {
+ struct audit_context_entry *ace;
+
+ audit_log_format(ab, " subj=?");
+ ace = kzalloc(sizeof(*ace), ab->gfp_mask);
+ if (!ace) {
+ error = -ENOMEM;
goto error_path;
- return 0;
+ }
+ INIT_LIST_HEAD(&ace->list);
+ ace->type = AUDIT_MAC_TASK_CONTEXTS;
+ ace->lsm_subjs = blob;
+ list_add(&ace->list, &ab->aux_records);
}
-
- audit_log_format(ab, " subj=%s", context.context);
- security_release_secctx(&context);
return 0;
error_path:
@@ -2434,9 +2452,12 @@ void audit_log_end(struct audit_buffer *ab)
struct audit_context_entry *entry;
struct audit_context mcontext;
struct audit_context *mctx;
+ struct lsmcontext lcontext;
struct audit_buffer *mab;
struct list_head *l;
struct list_head *n;
+ int rc;
+ int i;
if (!ab)
return;
@@ -2449,6 +2470,7 @@ void audit_log_end(struct audit_buffer *ab)
}
if (ab->ctx == NULL) {
+ mcontext.context = AUDIT_CTX_SYSCALL;
mcontext.stamp = ab->stamp;
mctx = &mcontext;
} else
@@ -2462,7 +2484,27 @@ void audit_log_end(struct audit_buffer *ab)
continue;
}
switch (entry->type) {
- /* Don't know of any quite yet. */
+ case AUDIT_MAC_TASK_CONTEXTS:
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (entry->lsm_subjs.secid[i] == 0)
+ continue;
+ rc = security_secid_to_secctx(&entry->lsm_subjs,
+ &lcontext, i);
+ if (rc) {
+ if (rc != -EINVAL)
+ audit_panic("error in audit_log_end");
+ audit_log_format(mab, "%ssubj_%s=?",
+ i ? " " : "",
+ lsm_slot_to_name(i));
+ } else {
+ audit_log_format(mab, "%ssubj_%s=%s",
+ i ? " " : "",
+ lsm_slot_to_name(i),
+ lcontext.context);
+ security_release_secctx(&lcontext);
+ }
+ }
+ break;
default:
audit_panic("Unknown type in audit_log_end");
break;
--
2.31.1
Send an identifier for the security module interface_lsm
along with the security context. This allows the receiver
to verify that the receiver and the sender agree on which
security module's context is being used. If they don't
agree the message is rejected.
Signed-off-by: Casey Schaufler <[email protected]>
---
drivers/android/binder.c | 21 +++++++++++++++++++++
drivers/android/binder_internal.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index b0b0c132a247..259f5e38e6ba 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3024,6 +3024,7 @@ static void binder_transaction(struct binder_proc *proc,
ALIGN(extra_buffers_size, sizeof(void *)) -
ALIGN(lsmctx.len, sizeof(u64));
+ t->security_interface = lsm_task_ilsm(current);
t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
err = binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
@@ -4453,6 +4454,26 @@ static int binder_thread_read(struct binder_proc *proc,
tr.secctx = t->security_ctx;
if (t->security_ctx) {
+ int to_ilsm = lsm_task_ilsm(current);
+ int from_ilsm = t->security_interface;
+
+ if (to_ilsm == LSMBLOB_INVALID)
+ to_ilsm = 0;
+ if (from_ilsm == LSMBLOB_INVALID)
+ from_ilsm = 0;
+ /*
+ * The sender provided a security context from
+ * a different security module than the one this
+ * process wants to report if these don't match.
+ */
+ if (from_ilsm != to_ilsm) {
+ if (t_from)
+ binder_thread_dec_tmpref(t_from);
+
+ binder_cleanup_transaction(t, "security context mismatch",
+ BR_FAILED_REPLY);
+ return -EINVAL;
+ }
cmd = BR_TRANSACTION_SEC_CTX;
trsize = sizeof(tr);
}
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index d6b6b8cb7346..e3a0718ce17c 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -545,6 +545,7 @@ struct binder_transaction {
long saved_priority;
kuid_t sender_euid;
struct list_head fd_fixups;
+ int security_interface;
binder_uintptr_t security_ctx;
/**
* @lock: protects @from, @to_proc, and @to_thread
--
2.31.1
Create a new audit record AUDIT_MAC_OBJ_CONTEXTS.
An example of the MAC_OBJ_CONTEXTS (1421) record is:
type=MAC_OBJ_CONTEXTS[1421]
msg=audit(1601152467.009:1050):
obj_selinux=unconfined_u:object_r:user_home_t:s0
When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record
the "obj=" field in other records in the event will be "obj=?".
An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has
multiple security modules that may make access decisions based
on an object security context.
Signed-off-by: Casey Schaufler <[email protected]>
---
include/linux/audit.h | 5 ++++
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 59 ++++++++++++++++++++++++++++++++++++++
kernel/auditsc.c | 37 ++++--------------------
4 files changed, 70 insertions(+), 32 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 14849d5f84b4..94c87ec043c7 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -192,6 +192,8 @@ 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 void 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);
@@ -255,6 +257,9 @@ static inline int audit_log_task_context(struct audit_buffer *ab)
{
return 0;
}
+static inline void audit_log_object_context(struct audit_buffer *ab,
+ struct lsmblob *blob);
+{ }
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 af0aaccfaf57..d25d76b29e3c 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -144,6 +144,7 @@
#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 task contexts */
+#define AUDIT_MAC_OBJ_CONTEXTS 1421 /* Multiple LSM objext 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 e8744e80ef21..3b9ce617b150 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -199,6 +199,7 @@ struct audit_context_entry {
int type; /* Audit record type */
union {
struct lsmblob lsm_subjs;
+ struct lsmblob lsm_objs;
};
};
@@ -2199,6 +2200,43 @@ int audit_log_task_context(struct audit_buffer *ab)
}
EXPORT_SYMBOL(audit_log_task_context);
+void audit_log_object_context(struct audit_buffer *ab, struct lsmblob *blob)
+{
+ struct audit_context_entry *ace;
+ struct lsmcontext context;
+ int error;
+
+ if (!lsm_multiple_contexts()) {
+ error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST);
+ if (error) {
+ if (error != -EINVAL)
+ goto error_path;
+ return;
+ }
+ audit_log_format(ab, " obj=%s", context.context);
+ security_release_secctx(&context);
+ } else {
+ /*
+ * 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.
+ */
+ audit_log_format(ab, " obj=?");
+ ace = kzalloc(sizeof(*ace), ab->gfp_mask);
+ if (!ace)
+ goto error_path;
+ INIT_LIST_HEAD(&ace->list);
+ ace->type = AUDIT_MAC_OBJ_CONTEXTS;
+ ace->lsm_objs = *blob;
+ list_add(&ace->list, &ab->aux_records);
+ }
+ return;
+
+error_path:
+ audit_panic("error in audit_log_object_context");
+}
+EXPORT_SYMBOL(audit_log_object_context);
+
void audit_log_d_path_exe(struct audit_buffer *ab,
struct mm_struct *mm)
{
@@ -2505,6 +2543,27 @@ void audit_log_end(struct audit_buffer *ab)
}
}
break;
+ case AUDIT_MAC_OBJ_CONTEXTS:
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (entry->lsm_objs.secid[i] == 0)
+ continue;
+ rc = security_secid_to_secctx(&entry->lsm_objs,
+ &lcontext, i);
+ if (rc) {
+ if (rc != -EINVAL)
+ audit_panic("error in audit_log_end");
+ audit_log_format(mab, "%sobj_%s=?",
+ i ? " " : "",
+ lsm_slot_to_name(i));
+ } else {
+ audit_log_format(mab, "%sobj_%s=%s",
+ i ? " " : "",
+ lsm_slot_to_name(i),
+ lcontext.context);
+ security_release_secctx(&lcontext);
+ }
+ }
+ break;
default:
audit_panic("Unknown type in audit_log_end");
break;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 7848e7351cf9..41111b607c78 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1120,7 +1120,6 @@ 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);
@@ -1130,15 +1129,8 @@ 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))
+ audit_log_object_context(ab, blob);
audit_log_format(ab, " ocomm=");
audit_log_untrustedstring(ab, comm);
audit_log_end(ab);
@@ -1373,18 +1365,10 @@ static void show_special(struct audit_context *context, int *call_panic)
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);
- }
+ audit_log_object_context(ab, &blob);
}
if (context->ipc.has_perm) {
audit_log_end(ab);
@@ -1536,19 +1520,8 @@ 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 (lsmblob_is_set(&n->lsmblob)) {
- struct lsmcontext lsmctx;
-
- if (security_secid_to_secctx(&n->lsmblob, &lsmctx,
- LSMBLOB_FIRST)) {
- audit_log_format(ab, " 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->lsmblob))
+ audit_log_object_context(ab, &n->lsmblob);
/* log the audit_names record type */
switch (n->type) {
--
2.31.1
Replace the osid field in the audit_names structure
with a lsmblob structure. This accomodates the use
of an lsmblob in security_audit_rule_match() and
security_inode_getsecid().
Signed-off-by: Casey Schaufler <[email protected]>
Acked-by: Paul Moore <[email protected]>
---
kernel/audit.h | 2 +-
kernel/auditsc.c | 22 ++++++++--------------
2 files changed, 9 insertions(+), 15 deletions(-)
diff --git a/kernel/audit.h b/kernel/audit.h
index 527d4c4acb12..a2fca1134519 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -82,7 +82,7 @@ struct audit_names {
kuid_t uid;
kgid_t gid;
dev_t rdev;
- u32 osid;
+ struct lsmblob lsmblob;
struct audit_cap_data fcap;
unsigned int fcap_ver;
unsigned char type; /* record type */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e091d03f9184..47d34433b91e 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -700,17 +700,16 @@ static int audit_filter_rules(struct task_struct *tsk,
* lsmblob, which happens later in
* this patch set.
*/
- lsmblob_init(&blob, name->osid);
result = security_audit_rule_match(
- &blob,
+ &name->lsmblob,
f->type,
f->op,
&f->lsm_rules);
} else if (ctx) {
list_for_each_entry(n, &ctx->names_list, list) {
- lsmblob_init(&blob, n->osid);
if (security_audit_rule_match(
- &blob, f->type, f->op,
+ &n->lsmblob,
+ f->type, f->op,
&f->lsm_rules)) {
++result;
break;
@@ -1537,13 +1536,12 @@ 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;
+ if (lsmblob_is_set(&n->lsmblob)) {
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 (security_secid_to_secctx(&n->lsmblob, &lsmctx,
+ LSMBLOB_FIRST)) {
+ audit_log_format(ab, " osid=?");
if (call_panic)
*call_panic = 2;
} else {
@@ -2245,17 +2243,13 @@ 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->lsmblob);
if (flags & AUDIT_INODE_NOEVAL) {
name->fcap_ver = -1;
return;
--
2.31.1
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 44843d665f35..62178dd4ec08 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -519,7 +519,7 @@ 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);
@@ -1276,9 +1276,10 @@ 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 5edb16cb12e0..598e0de45b04 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2610,12 +2610,17 @@ 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 ffdd366d2098..815200684bcf 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1999,10 +1999,16 @@ 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
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 1a7e5bf36a82..6da0c12c9170 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -194,6 +194,10 @@ 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 2bf21c726ba0..03a0af7e9e81 100644
--- a/security/security.c
+++ b/security/security.c
@@ -477,6 +477,50 @@ 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.
@@ -498,6 +542,7 @@ 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
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.
Signed-off-by: Casey Schaufler <[email protected]>
Acked-by: Paul Moore <[email protected]>
Cc: [email protected]
---
include/linux/security.h | 5 +++--
kernel/auditfilter.c | 6 ++++--
kernel/auditsc.c | 16 +++++++++++-----
security/security.c | 5 +++--
4 files changed, 21 insertions(+), 11 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 1edbb362ee72..3b734ebb7e29 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1946,7 +1946,7 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
int security_audit_rule_init(u32 field, u32 op, char *rulestr,
struct audit_lsm_rules *lsmrules);
int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op,
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
struct audit_lsm_rules *lsmrules);
void security_audit_rule_free(struct audit_lsm_rules *lsmrules);
@@ -1963,7 +1963,8 @@ 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,
+static inline int security_audit_rule_match(struct lsmblob *blob,
+ u32 field, u32 op,
struct audit_lsm_rules *lsmrules)
{
return 0;
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index de75bd6ad866..15cd4fe35e9c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1337,6 +1337,7 @@ 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];
+ struct lsmblob blob;
pid_t pid;
u32 sid;
@@ -1369,8 +1370,9 @@ int audit_filter(int msgtype, unsigned int listtype)
case AUDIT_SUBJ_CLR:
if (f->lsm_str) {
security_current_getsecid_subj(&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 f1c26a322f9d..e5ca89160b5f 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -468,6 +468,7 @@ 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;
if (ctx && rule->prio <= ctx->prio)
@@ -678,8 +679,10 @@ static int audit_filter_rules(struct task_struct *tsk,
security_current_getsecid_subj(&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:
@@ -692,15 +695,17 @@ static int audit_filter_rules(struct task_struct *tsk,
if (f->lsm_str) {
/* 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, n->osid);
if (security_audit_rule_match(
- n->osid, f->type, f->op,
+ &blob, f->type, f->op,
&f->lsm_rules)) {
++result;
break;
@@ -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/security.c b/security/security.c
index 29fc50322b1f..5b2dc867c57d 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2683,7 +2683,7 @@ void security_audit_rule_free(struct audit_lsm_rules *lsmrules)
}
}
-int security_audit_rule_match(u32 secid, u32 field, u32 op,
+int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op,
struct audit_lsm_rules *lsmrules)
{
struct security_hook_list *hp;
@@ -2694,7 +2694,8 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op,
continue;
if (lsmrules->rule[hp->lsmid->slot] == NULL)
continue;
- rc = hp->hook.audit_rule_match(secid, field, op,
+ rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot],
+ field, op,
&lsmrules->rule[hp->lsmid->slot]);
if (rc)
return rc;
--
2.31.1
On 3/3/2022 3:36 PM, Paul Moore wrote:
> On Wed, Feb 2, 2022 at 7:20 PM Casey Schaufler <[email protected]> wrote:
>> Add a list for auxiliary record data to the audit_buffer structure.
>> Add the audit_stamp information to the audit_buffer as there's no
>> guarantee that there will be an audit_context containing the stamp
>> associated with the event. At audit_log_end() time create auxiliary
>> records (none are currently defined) as have been added to the list.
>>
>> Signed-off-by: Casey Schaufler <[email protected]>
>> ---
>> kernel/audit.c | 84 ++++++++++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 74 insertions(+), 10 deletions(-)
>>
>> diff --git a/kernel/audit.c b/kernel/audit.c
>> index f012c3786264..559fb14e0380 100644
>> --- a/kernel/audit.c
>> +++ b/kernel/audit.c
>> @@ -191,15 +191,25 @@ static struct audit_ctl_mutex {
>> * should be at least that large. */
>> #define AUDIT_BUFSIZ 1024
>>
>> +/* The audit_context_entry contains data required to create an
>> + * auxiliary record.
>> + */
>> +struct audit_context_entry {
>> + struct list_head list;
>> + int type; /* Audit record type */
>> +};
> Looking at how this ends up being used later in the patchset I think
> we would be better off if we stored a fully formed audit_buffer in the
> struct above instead of data fields which we would use to generate an
> audit_buffer in audit_log_end(). This helps tie the buffer generation
> logic in with the existing code with which it is most closely related,
> it allows us to report errors back to the caller as audit_log_end()
> doesn't historically return an error code, and it helps us get ahead
> of any future data lifetime issues we might run into by storing the
> data in this audit struct.
OK, I'll buy that.
> This would also simplify things with respect to the audit_buffer
> struct. Instead of having a dedicated struct for the aux data, you
> could simply leverage the existing sk_buff list mechanisms:
I can't say that "simply" is the adverb I'd choose, but sure,
I can do this.
> struct audit_buffer {
> struct sk_buff *skb; /* part of @skb_list, kept for audit_log funcs */
> struct sk_buff_head skb_list;
> struct audit_context *ctx;
> struct audit_stamp stamp;
> gfp_t gfp_mask;
> }
>
> The only sneaky bit in the struct above is that we likely want to
> preserve audit_buffer::skb as a dedicated skb pointer so we don't have
> to modify all of the audit_log_*() functions; you could of course, but
> I'm guessing there is little appetite for that in the context of this
> patchset.
I will give it a go without making the massive interface change.
> Adding a new aux record would involve calling some private audit
> function (no one outside of the audit subsystem should need access)
> that would allocate a new skb similar to what we do in
> audit_buffer_alloc() and add it to the end of the sk_buff_head list
> via skb_queue_tail() and resetting audit_buffer::skb to point to the
> newly allocated skb.
Good naming may be tricky as we need to indicate that a new buffer is
being allocated for an attached aux record and that the buffer to which
it's being attached is going to temporarily be in a curious state.
audit_buffer_add_aux() seems wordy, but it's what I'll start with lacking
a better suggestion.
> This would allow all of the existing
> audit_log*() functions to work correctly, and when you are done you
> can restore the "main" skb with skb_peek().
audit_buffer_close_aux()
> If for some reason you
> need to fail the new aux record mid-creation you just dequeue the list
> tail, free the skb, and skb_peek() the "main" skb back into place.
Why do I always get nervous when I hear "just" and "skb" in the
same sentence?
>> /* The audit_buffer is used when formatting an audit record. The caller
>> * locks briefly to get the record off the freelist or to allocate the
>> * buffer, and locks briefly to send the buffer to the netlink layer or
>> * to place it on a transmit queue. Multiple audit_buffers can be in
>> * use simultaneously. */
>> struct audit_buffer {
>> - struct sk_buff *skb; /* formatted skb ready to send */
>> - struct audit_context *ctx; /* NULL or associated context */
>> - gfp_t gfp_mask;
>> + struct sk_buff *skb; /* formatted skb ready to send */
>> + struct audit_context *ctx; /* NULL or associated context */
>> + struct list_head aux_records; /* aux record data */
>> + struct audit_stamp stamp; /* event stamp */
>> + gfp_t gfp_mask;
>> };
> ...
>
>> @@ -2408,6 +2418,60 @@ void audit_log_end(struct audit_buffer *ab)
>> wake_up_interruptible(&kauditd_wait);
>> } else
>> audit_log_lost("rate limit exceeded");
>> +}
>> +
>> +/**
>> + * audit_log_end - end one audit record
>> + * @ab: the audit_buffer
>> + *
>> + * Let __audit_log_end() handle the message while the buffer housekeeping
>> + * is done here.
>> + * If there are other records that have been deferred for the event
>> + * create them here.
>> + */
>> +void audit_log_end(struct audit_buffer *ab)
>> +{
>> + struct audit_context_entry *entry;
>> + struct audit_context mcontext;
>> + struct audit_context *mctx;
>> + struct audit_buffer *mab;
>> + struct list_head *l;
>> + struct list_head *n;
>> +
>> + if (!ab)
>> + return;
>> +
>> + __audit_log_end(ab);
>> +
>> + if (list_empty(&ab->aux_records)) {
>> + audit_buffer_free(ab);
>> + return;
>> + }
>> +
>> + if (ab->ctx == NULL) {
>> + mcontext.stamp = ab->stamp;
>> + mctx = &mcontext;
>> + } else
>> + mctx = ab->ctx;
>> +
>> + list_for_each_safe(l, n, &ab->aux_records) {
>> + entry = list_entry(l, struct audit_context_entry, list);
>> + mab = audit_log_start(mctx, ab->gfp_mask, entry->type);
>> + if (!mab) {
>> + audit_panic("alloc error in audit_log_end");
>> + continue;
>> + }
>> + switch (entry->type) {
>> + /* Don't know of any quite yet. */
>> + default:
>> + audit_panic("Unknown type in audit_log_end");
>> + break;
>> + }
>> + __audit_log_end(mab);
>> + audit_buffer_free(mab);
>> + list_del(&entry->list);
>> + kfree(entry);
>> + }
>>
>> audit_buffer_free(ab);
>> }
> This would also allow you to simplify audit_log_end() greatly, I'm
> sure I'm missing a detail or two, but I suspect it would end up
> looking something like this:
Agreed. That is a much better fit for the existing code flow.
>
> void __audit_log_end(skb)
> {
> /* ... current audit_log_end() but with only the sk_buff ... */
> }
>
> void audit_log_end(ab)
> {
> if (!ab)
> return;
> while ((skb = skb_dequeue(ab->skb_list)))
> __audit_log_end(skb);
> audit_buffer_free(ab);
> }
>
>
> --
> paul-moore.com
On Wed, Feb 2, 2022 at 7:20 PM Casey Schaufler <[email protected]> wrote:
>
> Add a list for auxiliary record data to the audit_buffer structure.
> Add the audit_stamp information to the audit_buffer as there's no
> guarantee that there will be an audit_context containing the stamp
> associated with the event. At audit_log_end() time create auxiliary
> records (none are currently defined) as have been added to the list.
>
> Signed-off-by: Casey Schaufler <[email protected]>
> ---
> kernel/audit.c | 84 ++++++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 74 insertions(+), 10 deletions(-)
>
> diff --git a/kernel/audit.c b/kernel/audit.c
> index f012c3786264..559fb14e0380 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -191,15 +191,25 @@ static struct audit_ctl_mutex {
> * should be at least that large. */
> #define AUDIT_BUFSIZ 1024
>
> +/* The audit_context_entry contains data required to create an
> + * auxiliary record.
> + */
> +struct audit_context_entry {
> + struct list_head list;
> + int type; /* Audit record type */
> +};
Looking at how this ends up being used later in the patchset I think
we would be better off if we stored a fully formed audit_buffer in the
struct above instead of data fields which we would use to generate an
audit_buffer in audit_log_end(). This helps tie the buffer generation
logic in with the existing code with which it is most closely related,
it allows us to report errors back to the caller as audit_log_end()
doesn't historically return an error code, and it helps us get ahead
of any future data lifetime issues we might run into by storing the
data in this audit struct.
This would also simplify things with respect to the audit_buffer
struct. Instead of having a dedicated struct for the aux data, you
could simply leverage the existing sk_buff list mechanisms:
struct audit_buffer {
struct sk_buff *skb; /* part of @skb_list, kept for audit_log funcs */
struct sk_buff_head skb_list;
struct audit_context *ctx;
struct audit_stamp stamp;
gfp_t gfp_mask;
}
The only sneaky bit in the struct above is that we likely want to
preserve audit_buffer::skb as a dedicated skb pointer so we don't have
to modify all of the audit_log_*() functions; you could of course, but
I'm guessing there is little appetite for that in the context of this
patchset.
Adding a new aux record would involve calling some private audit
function (no one outside of the audit subsystem should need access)
that would allocate a new skb similar to what we do in
audit_buffer_alloc() and add it to the end of the sk_buff_head list
via skb_queue_tail() and resetting audit_buffer::skb to point to the
newly allocated skb. This would allow all of the existing
audit_log*() functions to work correctly, and when you are done you
can restore the "main" skb with skb_peek(). If for some reason you
need to fail the new aux record mid-creation you just dequeue the list
tail, free the skb, and skb_peek() the "main" skb back into place.
> /* The audit_buffer is used when formatting an audit record. The caller
> * locks briefly to get the record off the freelist or to allocate the
> * buffer, and locks briefly to send the buffer to the netlink layer or
> * to place it on a transmit queue. Multiple audit_buffers can be in
> * use simultaneously. */
> struct audit_buffer {
> - struct sk_buff *skb; /* formatted skb ready to send */
> - struct audit_context *ctx; /* NULL or associated context */
> - gfp_t gfp_mask;
> + struct sk_buff *skb; /* formatted skb ready to send */
> + struct audit_context *ctx; /* NULL or associated context */
> + struct list_head aux_records; /* aux record data */
> + struct audit_stamp stamp; /* event stamp */
> + gfp_t gfp_mask;
> };
...
> @@ -2408,6 +2418,60 @@ void audit_log_end(struct audit_buffer *ab)
> wake_up_interruptible(&kauditd_wait);
> } else
> audit_log_lost("rate limit exceeded");
> +}
> +
> +/**
> + * audit_log_end - end one audit record
> + * @ab: the audit_buffer
> + *
> + * Let __audit_log_end() handle the message while the buffer housekeeping
> + * is done here.
> + * If there are other records that have been deferred for the event
> + * create them here.
> + */
> +void audit_log_end(struct audit_buffer *ab)
> +{
> + struct audit_context_entry *entry;
> + struct audit_context mcontext;
> + struct audit_context *mctx;
> + struct audit_buffer *mab;
> + struct list_head *l;
> + struct list_head *n;
> +
> + if (!ab)
> + return;
> +
> + __audit_log_end(ab);
> +
> + if (list_empty(&ab->aux_records)) {
> + audit_buffer_free(ab);
> + return;
> + }
> +
> + if (ab->ctx == NULL) {
> + mcontext.stamp = ab->stamp;
> + mctx = &mcontext;
> + } else
> + mctx = ab->ctx;
> +
> + list_for_each_safe(l, n, &ab->aux_records) {
> + entry = list_entry(l, struct audit_context_entry, list);
> + mab = audit_log_start(mctx, ab->gfp_mask, entry->type);
> + if (!mab) {
> + audit_panic("alloc error in audit_log_end");
> + continue;
> + }
> + switch (entry->type) {
> + /* Don't know of any quite yet. */
> + default:
> + audit_panic("Unknown type in audit_log_end");
> + break;
> + }
> + __audit_log_end(mab);
> + audit_buffer_free(mab);
> + list_del(&entry->list);
> + kfree(entry);
> + }
>
> audit_buffer_free(ab);
> }
This would also allow you to simplify audit_log_end() greatly, I'm
sure I'm missing a detail or two, but I suspect it would end up
looking something like this:
void __audit_log_end(skb)
{
/* ... current audit_log_end() but with only the sk_buff ... */
}
void audit_log_end(ab)
{
if (!ab)
return;
while ((skb = skb_dequeue(ab->skb_list)))
__audit_log_end(skb);
audit_buffer_free(ab);
}
--
paul-moore.com
On 3/3/2022 3:36 PM, Paul Moore wrote:
> On Wed, Feb 2, 2022 at 7:23 PM Casey Schaufler <[email protected]> wrote:
>> Create a new audit record AUDIT_MAC_OBJ_CONTEXTS.
>> An example of the MAC_OBJ_CONTEXTS (1421) record is:
>>
>> type=MAC_OBJ_CONTEXTS[1421]
>> msg=audit(1601152467.009:1050):
>> obj_selinux=unconfined_u:object_r:user_home_t:s0
>>
>> When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record
>> the "obj=" field in other records in the event will be "obj=?".
>> An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has
>> multiple security modules that may make access decisions based
>> on an object security context.
>>
>> Signed-off-by: Casey Schaufler <[email protected]>
>> ---
>> include/linux/audit.h | 5 ++++
>> include/uapi/linux/audit.h | 1 +
>> kernel/audit.c | 59 ++++++++++++++++++++++++++++++++++++++
>> kernel/auditsc.c | 37 ++++--------------------
>> 4 files changed, 70 insertions(+), 32 deletions(-)
> ...
>
>> diff --git a/kernel/audit.c b/kernel/audit.c
>> index e8744e80ef21..3b9ce617b150 100644
>> --- a/kernel/audit.c
>> +++ b/kernel/audit.c
>> @@ -2199,6 +2200,43 @@ int audit_log_task_context(struct audit_buffer *ab)
>> }
>> EXPORT_SYMBOL(audit_log_task_context);
>>
>> +void audit_log_object_context(struct audit_buffer *ab, struct lsmblob *blob)
>> +{
>> + struct audit_context_entry *ace;
>> + struct lsmcontext context;
>> + int error;
>> +
>> + if (!lsm_multiple_contexts()) {
>> + error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST);
>> + if (error) {
>> + if (error != -EINVAL)
>> + goto error_path;
>> + return;
>> + }
>> + audit_log_format(ab, " obj=%s", context.context);
>> + security_release_secctx(&context);
>> + } else {
>> + /*
>> + * 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.
>> + */
> I know this is nitpicky, but I'm going to say it anyway ... the
> separate record isn't purely for compatibility reasons, it's for size
> reasons. There is a fear that multiple LSM labels could blow past the
> record size limit when combined with other fields, so putting them in
> their own dedicated record gives us more room. If that wasn't the
> case we could just tack them on the end of existing records.
Fair enough. I have no objection to adding commentary that will
help the next developer who comes into this code.
>
> However, converting the existing "obj=" field into "obj=?" when
> multiple LSM labels are present *is* a compatibility nod as it allows
> existing userspace tooling that expects a single "obj=" field to
> continue to work.
Likewise here.
>
>> + audit_log_format(ab, " obj=?");
>> + ace = kzalloc(sizeof(*ace), ab->gfp_mask);
>> + if (!ace)
>> + goto error_path;
>> + INIT_LIST_HEAD(&ace->list);
>> + ace->type = AUDIT_MAC_OBJ_CONTEXTS;
>> + ace->lsm_objs = *blob;
>> + list_add(&ace->list, &ab->aux_records);
>> + }
>> + return;
>> +
>> +error_path:
>> + audit_panic("error in audit_log_object_context");
>> +}
>> +EXPORT_SYMBOL(audit_log_object_context);
>> +
On Wed, Feb 2, 2022 at 7:23 PM Casey Schaufler <[email protected]> wrote:
>
> Create a new audit record AUDIT_MAC_OBJ_CONTEXTS.
> An example of the MAC_OBJ_CONTEXTS (1421) record is:
>
> type=MAC_OBJ_CONTEXTS[1421]
> msg=audit(1601152467.009:1050):
> obj_selinux=unconfined_u:object_r:user_home_t:s0
>
> When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record
> the "obj=" field in other records in the event will be "obj=?".
> An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has
> multiple security modules that may make access decisions based
> on an object security context.
>
> Signed-off-by: Casey Schaufler <[email protected]>
> ---
> include/linux/audit.h | 5 ++++
> include/uapi/linux/audit.h | 1 +
> kernel/audit.c | 59 ++++++++++++++++++++++++++++++++++++++
> kernel/auditsc.c | 37 ++++--------------------
> 4 files changed, 70 insertions(+), 32 deletions(-)
...
> diff --git a/kernel/audit.c b/kernel/audit.c
> index e8744e80ef21..3b9ce617b150 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2199,6 +2200,43 @@ int audit_log_task_context(struct audit_buffer *ab)
> }
> EXPORT_SYMBOL(audit_log_task_context);
>
> +void audit_log_object_context(struct audit_buffer *ab, struct lsmblob *blob)
> +{
> + struct audit_context_entry *ace;
> + struct lsmcontext context;
> + int error;
> +
> + if (!lsm_multiple_contexts()) {
> + error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST);
> + if (error) {
> + if (error != -EINVAL)
> + goto error_path;
> + return;
> + }
> + audit_log_format(ab, " obj=%s", context.context);
> + security_release_secctx(&context);
> + } else {
> + /*
> + * 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.
> + */
I know this is nitpicky, but I'm going to say it anyway ... the
separate record isn't purely for compatibility reasons, it's for size
reasons. There is a fear that multiple LSM labels could blow past the
record size limit when combined with other fields, so putting them in
their own dedicated record gives us more room. If that wasn't the
case we could just tack them on the end of existing records.
However, converting the existing "obj=" field into "obj=?" when
multiple LSM labels are present *is* a compatibility nod as it allows
existing userspace tooling that expects a single "obj=" field to
continue to work.
> + audit_log_format(ab, " obj=?");
> + ace = kzalloc(sizeof(*ace), ab->gfp_mask);
> + if (!ace)
> + goto error_path;
> + INIT_LIST_HEAD(&ace->list);
> + ace->type = AUDIT_MAC_OBJ_CONTEXTS;
> + ace->lsm_objs = *blob;
> + list_add(&ace->list, &ab->aux_records);
> + }
> + return;
> +
> +error_path:
> + audit_panic("error in audit_log_object_context");
> +}
> +EXPORT_SYMBOL(audit_log_object_context);
> +
--
paul-moore.com
On Thu, Mar 3, 2022 at 9:13 PM Casey Schaufler <[email protected]> wrote:
> On 3/3/2022 3:36 PM, Paul Moore wrote:
> > Adding a new aux record would involve calling some private audit
> > function (no one outside of the audit subsystem should need access)
> > that would allocate a new skb similar to what we do in
> > audit_buffer_alloc() and add it to the end of the sk_buff_head list
> > via skb_queue_tail() and resetting audit_buffer::skb to point to the
> > newly allocated skb.
>
> Good naming may be tricky as we need to indicate that a new buffer is
> being allocated for an attached aux record and that the buffer to which
> it's being attached is going to temporarily be in a curious state.
> audit_buffer_add_aux() seems wordy, but it's what I'll start with lacking
> a better suggestion.
I agree that it will leave the audit_buffer in an odd state, at least
with the current definition of the audit_buffer. However, this is
mitigated by the restriction that the only callers should be within
the audit subsystem. Here is some quick pseudo-code mockup of what
I'm thinking:
/* on success, ab->skb will point to the new aux record */
static int audit_buffer_aux_new(struct audit_buffer *ab, int type)
{
WARN_ON(ab->skb != skb_peek(&ab->skb_list));
ab->skb = nlmsg_new(AUDIT_BUFSIZ, ab->gfp_mask);
if (!ab->skb)
goto err;
if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
goto err;
skb_queue_tail(&ab->skb_list);
return 0;
err:
kfree_skb(&ab->skb);
ab->skb = skb_peek(&ab->skb_list);
return -ENOMEM;
}
/* restores the "main" record into ab->skb */
static void audit_buffer_aux_end(struct audit_buffer *ab)
{
ab->skb = skb_peek(&ab->skb_list);
}
/* free the current aux record and reset ab->skb to the "main" */
static void audit_buffer_aux_cancel(struct audit_buffer *ab)
{
if (ab->skb != skb_peek_tail(&ab->skb_list)) {
BUG();
return;
}
ab->skb = skb_peek(&ab->skb_list);
kfree_skb(skb_dequeue_tail(&ab->skb_list));
}
--
paul-moore.com