2021-02-19 22:26:20

by Olga Kornievskaia

[permalink] [raw]
Subject: [PATCH v3 1/3] [security] Add new hook to compare new mount to an existing mount

From: Olga Kornievskaia <[email protected]>

Add a new hook that takes an existing super block and a new mount
with new options and determines if new options confict with an
existing mount or not.

A filesystem can use this new hook to determine if it can share
the an existing superblock with a new superblock for the new mount.

Signed-off-by: Olga Kornievskaia <[email protected]>
---
include/linux/lsm_hook_defs.h | 1 +
include/linux/lsm_hooks.h | 6 ++++
include/linux/security.h | 8 +++++
security/security.c | 7 +++++
security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
5 files changed, 78 insertions(+)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 7aaa753b8608..1b12a5266a51 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -62,6 +62,7 @@ LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb)
LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
+LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a19adef1f088..d76aaecfdf0f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -142,6 +142,12 @@
* @orig the original mount data copied from userspace.
* @copy copied data which will be passed to the security module.
* Returns 0 if the copy was successful.
+ * @sb_mnt_opts_compat:
+ * Determine if the existing mount options are compatible with the new
+ * mount options being used.
+ * @sb superblock being compared
+ * @mnt_opts new mount options
+ * Return 0 if options are compatible.
* @sb_remount:
* Extracts security system specific mount options and verifies no changes
* are being made to those options.
diff --git a/include/linux/security.h b/include/linux/security.h
index c35ea0ffccd9..50db3d5d1608 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -291,6 +291,7 @@ int security_sb_alloc(struct super_block *sb);
void security_sb_free(struct super_block *sb);
void security_free_mnt_opts(void **mnt_opts);
int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
+int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
int security_sb_remount(struct super_block *sb, void *mnt_opts);
int security_sb_kern_mount(struct super_block *sb);
int security_sb_show_options(struct seq_file *m, struct super_block *sb);
@@ -635,6 +636,13 @@ static inline int security_sb_remount(struct super_block *sb,
return 0;
}

+static inline int security_sb_mnt_opts_compat(struct super_block *sb,
+ void *mnt_opts)
+{
+ return 0;
+}
+
+
static inline int security_sb_kern_mount(struct super_block *sb)
{
return 0;
diff --git a/security/security.c b/security/security.c
index 7b09cfbae94f..56cf5563efde 100644
--- a/security/security.c
+++ b/security/security.c
@@ -890,6 +890,13 @@ int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
}
EXPORT_SYMBOL(security_sb_eat_lsm_opts);

+int security_sb_mnt_opts_compat(struct super_block *sb,
+ void *mnt_opts)
+{
+ return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts);
+}
+EXPORT_SYMBOL(security_sb_mnt_opts_compat);
+
int security_sb_remount(struct super_block *sb,
void *mnt_opts)
{
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 644b17ec9e63..afee3a222a0e 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2656,6 +2656,61 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
return rc;
}

+static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
+{
+ struct selinux_mnt_opts *opts = mnt_opts;
+ struct superblock_security_struct *sbsec = sb->s_security;
+ u32 sid;
+ int rc;
+
+ /*
+ * Superblock not initialized (i.e. no options) - reject if any
+ * options specified, otherwise accept.
+ */
+ if (!(sbsec->flags & SE_SBINITIALIZED))
+ return opts ? 1 : 0;
+
+ /*
+ * Superblock initialized and no options specified - reject if
+ * superblock has any options set, otherwise accept.
+ */
+ if (!opts)
+ return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
+
+ if (opts->fscontext) {
+ rc = parse_sid(sb, opts->fscontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
+ return 1;
+ }
+ if (opts->context) {
+ rc = parse_sid(sb, opts->context, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
+ return 1;
+ }
+ if (opts->rootcontext) {
+ struct inode_security_struct *root_isec;
+
+ root_isec = backing_inode_security(sb->s_root);
+ rc = parse_sid(sb, opts->rootcontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
+ return 1;
+ }
+ if (opts->defcontext) {
+ rc = parse_sid(sb, opts->defcontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
+ return 1;
+ }
+ return 0;
+}
+
static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
{
struct selinux_mnt_opts *opts = mnt_opts;
@@ -6984,6 +7039,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {

LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
+ LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
--
2.27.0


2021-02-25 17:56:52

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v3 1/3] [security] Add new hook to compare new mount to an existing mount

On Fri, Feb 19, 2021 at 5:25 PM Olga Kornievskaia
<[email protected]> wrote:
>
> From: Olga Kornievskaia <[email protected]>
>
> Add a new hook that takes an existing super block and a new mount
> with new options and determines if new options confict with an
> existing mount or not.
>
> A filesystem can use this new hook to determine if it can share
> the an existing superblock with a new superblock for the new mount.
>
> Signed-off-by: Olga Kornievskaia <[email protected]>
> ---
> include/linux/lsm_hook_defs.h | 1 +
> include/linux/lsm_hooks.h | 6 ++++
> include/linux/security.h | 8 +++++
> security/security.c | 7 +++++
> security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
> 5 files changed, 78 insertions(+)

...

> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index a19adef1f088..d76aaecfdf0f 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -142,6 +142,12 @@
> * @orig the original mount data copied from userspace.
> * @copy copied data which will be passed to the security module.
> * Returns 0 if the copy was successful.
> + * @sb_mnt_opts_compat:
> + * Determine if the existing mount options are compatible with the new
> + * mount options being used.

Full disclosure: I'm a big fan of good documentation, regardless of if
it lives in comments or a separate dedicated resource. Looking at the
comment above, and the SELinux implementation of this hook below, it
appears that the comment is a bit vague; specifically the use of
"compatible". Based on the SELinux implementation, "compatible" would
seem to equal, do you envision that to be the case for every
LSM/security-model? If the answer is yes, then let's say that (and
possibly rename the hook to "sb_mnt_opts_equal"). If the answer is
no, then I think we need to do a better job explaining what
compatibility really means; put yourself in the shoes of someone
writing a LSM, what would they need to know to write an implementation
for this hook?

> + * @sb superblock being compared
> + * @mnt_opts new mount options
> + * Return 0 if options are compatible.

--
paul moore
http://www.paul-moore.com

2021-02-25 18:07:14

by Olga Kornievskaia

[permalink] [raw]
Subject: Re: [PATCH v3 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, Feb 25, 2021 at 12:53 PM Paul Moore <[email protected]> wrote:
>
> On Fri, Feb 19, 2021 at 5:25 PM Olga Kornievskaia
> <[email protected]> wrote:
> >
> > From: Olga Kornievskaia <[email protected]>
> >
> > Add a new hook that takes an existing super block and a new mount
> > with new options and determines if new options confict with an
> > existing mount or not.
> >
> > A filesystem can use this new hook to determine if it can share
> > the an existing superblock with a new superblock for the new mount.
> >
> > Signed-off-by: Olga Kornievskaia <[email protected]>
> > ---
> > include/linux/lsm_hook_defs.h | 1 +
> > include/linux/lsm_hooks.h | 6 ++++
> > include/linux/security.h | 8 +++++
> > security/security.c | 7 +++++
> > security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
> > 5 files changed, 78 insertions(+)
>
> ...
>
> > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> > index a19adef1f088..d76aaecfdf0f 100644
> > --- a/include/linux/lsm_hooks.h
> > +++ b/include/linux/lsm_hooks.h
> > @@ -142,6 +142,12 @@
> > * @orig the original mount data copied from userspace.
> > * @copy copied data which will be passed to the security module.
> > * Returns 0 if the copy was successful.
> > + * @sb_mnt_opts_compat:
> > + * Determine if the existing mount options are compatible with the new
> > + * mount options being used.
>
> Full disclosure: I'm a big fan of good documentation, regardless of if
> it lives in comments or a separate dedicated resource. Looking at the
> comment above, and the SELinux implementation of this hook below, it
> appears that the comment is a bit vague; specifically the use of
> "compatible". Based on the SELinux implementation, "compatible" would
> seem to equal, do you envision that to be the case for every
> LSM/security-model? If the answer is yes, then let's say that (and
> possibly rename the hook to "sb_mnt_opts_equal"). If the answer is
> no, then I think we need to do a better job explaining what
> compatibility really means; put yourself in the shoes of someone
> writing a LSM, what would they need to know to write an implementation
> for this hook?

That's is tough to do as it is vague. All I was doing was fixing a
bug. Selinux didn't allow a new mount because it had a different
security context. What that translates to for the new hook, is up to
the LSM module whether it would need the options to be exactly the
same or if they can be slightly different but yet compatible this is
really up to the LSM.

Do you care to suggest wording to use? It is hard to find words that
somebody else is looking for but one is unable to provide them.

>
> > + * @sb superblock being compared
> > + * @mnt_opts new mount options
> > + * Return 0 if options are compatible.
>
> --
> paul moore
> http://www.paul-moore.com

2021-02-25 18:25:06

by Casey Schaufler

[permalink] [raw]
Subject: Re: [PATCH v3 1/3] [security] Add new hook to compare new mount to an existing mount

On 2/25/2021 10:03 AM, Olga Kornievskaia wrote:
> On Thu, Feb 25, 2021 at 12:53 PM Paul Moore <[email protected]> wrote:
>> On Fri, Feb 19, 2021 at 5:25 PM Olga Kornievskaia
>> <[email protected]> wrote:
>>> From: Olga Kornievskaia <[email protected]>
>>>
>>> Add a new hook that takes an existing super block and a new mount
>>> with new options and determines if new options confict with an
>>> existing mount or not.
>>>
>>> A filesystem can use this new hook to determine if it can share
>>> the an existing superblock with a new superblock for the new mount.
>>>
>>> Signed-off-by: Olga Kornievskaia <[email protected]>
>>> ---
>>> include/linux/lsm_hook_defs.h | 1 +
>>> include/linux/lsm_hooks.h | 6 ++++
>>> include/linux/security.h | 8 +++++
>>> security/security.c | 7 +++++
>>> security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
>>> 5 files changed, 78 insertions(+)
>> ...
>>
>>> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
>>> index a19adef1f088..d76aaecfdf0f 100644
>>> --- a/include/linux/lsm_hooks.h
>>> +++ b/include/linux/lsm_hooks.h
>>> @@ -142,6 +142,12 @@
>>> * @orig the original mount data copied from userspace.
>>> * @copy copied data which will be passed to the security module.
>>> * Returns 0 if the copy was successful.
>>> + * @sb_mnt_opts_compat:
>>> + * Determine if the existing mount options are compatible with the new
>>> + * mount options being used.
>> Full disclosure: I'm a big fan of good documentation, regardless of if
>> it lives in comments or a separate dedicated resource. Looking at the
>> comment above, and the SELinux implementation of this hook below, it
>> appears that the comment is a bit vague; specifically the use of
>> "compatible". Based on the SELinux implementation, "compatible" would
>> seem to equal, do you envision that to be the case for every
>> LSM/security-model?

The original implementation did use sb_mnt_opts_equal(). The
change to "compatible" was my suggestion. Smack has multiple
mount options, and while I haven't actually delved into how
you would have compatible but different mount options, I
think it's possible. That's why I think that "equal" isn't
a good name for the function.

>> If the answer is yes, then let's say that (and
>> possibly rename the hook to "sb_mnt_opts_equal"). If the answer is
>> no, then I think we need to do a better job explaining what
>> compatibility really means; put yourself in the shoes of someone
>> writing a LSM, what would they need to know to write an implementation
>> for this hook?
> That's is tough to do as it is vague. All I was doing was fixing a
> bug. Selinux didn't allow a new mount because it had a different
> security context. What that translates to for the new hook, is up to
> the LSM module whether it would need the options to be exactly the
> same or if they can be slightly different but yet compatible this is
> really up to the LSM.
>
> Do you care to suggest wording to use? It is hard to find words that
> somebody else is looking for but one is unable to provide them.
>
>>> + * @sb superblock being compared
>>> + * @mnt_opts new mount options
>>> + * Return 0 if options are compatible.
>> --
>> paul moore
>> http://www.paul-moore.com

2021-02-25 19:35:23

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v3 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, Feb 25, 2021 at 1:03 PM Olga Kornievskaia
<[email protected]> wrote:
> On Thu, Feb 25, 2021 at 12:53 PM Paul Moore <[email protected]> wrote:
> > On Fri, Feb 19, 2021 at 5:25 PM Olga Kornievskaia
> > <[email protected]> wrote:
> > >
> > > From: Olga Kornievskaia <[email protected]>
> > >
> > > Add a new hook that takes an existing super block and a new mount
> > > with new options and determines if new options confict with an
> > > existing mount or not.
> > >
> > > A filesystem can use this new hook to determine if it can share
> > > the an existing superblock with a new superblock for the new mount.
> > >
> > > Signed-off-by: Olga Kornievskaia <[email protected]>
> > > ---
> > > include/linux/lsm_hook_defs.h | 1 +
> > > include/linux/lsm_hooks.h | 6 ++++
> > > include/linux/security.h | 8 +++++
> > > security/security.c | 7 +++++
> > > security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
> > > 5 files changed, 78 insertions(+)
> >
> > ...
> >
> > > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> > > index a19adef1f088..d76aaecfdf0f 100644
> > > --- a/include/linux/lsm_hooks.h
> > > +++ b/include/linux/lsm_hooks.h
> > > @@ -142,6 +142,12 @@
> > > * @orig the original mount data copied from userspace.
> > > * @copy copied data which will be passed to the security module.
> > > * Returns 0 if the copy was successful.
> > > + * @sb_mnt_opts_compat:
> > > + * Determine if the existing mount options are compatible with the new
> > > + * mount options being used.
> >
> > Full disclosure: I'm a big fan of good documentation, regardless of if
> > it lives in comments or a separate dedicated resource. Looking at the
> > comment above, and the SELinux implementation of this hook below, it
> > appears that the comment is a bit vague; specifically the use of
> > "compatible". Based on the SELinux implementation, "compatible" would
> > seem to equal, do you envision that to be the case for every
> > LSM/security-model? If the answer is yes, then let's say that (and
> > possibly rename the hook to "sb_mnt_opts_equal"). If the answer is
> > no, then I think we need to do a better job explaining what
> > compatibility really means; put yourself in the shoes of someone
> > writing a LSM, what would they need to know to write an implementation
> > for this hook?
>
> That's is tough to do as it is vague. All I was doing was fixing a
> bug. Selinux didn't allow a new mount because it had a different
> security context. What that translates to for the new hook, is up to
> the LSM module whether it would need the options to be exactly the
> same or if they can be slightly different but yet compatible this is
> really up to the LSM.
>
> Do you care to suggest wording to use? It is hard to find words that
> somebody else is looking for but one is unable to provide them.

I didn't have anything particular in mind, I just *really* don't like
the ambiguity around "compatible". Perhaps we can take away some of
the ambiguity by providing some more explanation, how about something
like this:

"Determine if the new mount options in @mnt_opts are allowed given the
existing mounted filesystem at @sb."

... it's a pretty minor change, I'll readily admit that, but it
exchanges "compatible" for "allowed" which I *think* makes it a bit
more concrete.

--
paul moore
http://www.paul-moore.com

2021-02-27 03:39:32

by Olga Kornievskaia

[permalink] [raw]
Subject: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

From: Olga Kornievskaia <[email protected]>

Add a new hook that takes an existing super block and a new mount
with new options and determines if new options confict with an
existing mount or not.

A filesystem can use this new hook to determine if it can share
the an existing superblock with a new superblock for the new mount.

Signed-off-by: Olga Kornievskaia <[email protected]>
---
include/linux/lsm_hook_defs.h | 1 +
include/linux/lsm_hooks.h | 6 ++++
include/linux/security.h | 8 +++++
security/security.c | 7 +++++
security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
5 files changed, 78 insertions(+)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 7aaa753b8608..1b12a5266a51 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -62,6 +62,7 @@ LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb)
LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
+LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a19adef1f088..0de8eb2ea547 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -142,6 +142,12 @@
* @orig the original mount data copied from userspace.
* @copy copied data which will be passed to the security module.
* Returns 0 if the copy was successful.
+ * @sb_mnt_opts_compat:
+ * Determine if the new mount options in @mnt_opts are allowed given
+ * the existing mounted filesystem at @sb.
+ * @sb superblock being compared
+ * @mnt_opts new mount options
+ * Return 0 if options are compatible.
* @sb_remount:
* Extracts security system specific mount options and verifies no changes
* are being made to those options.
diff --git a/include/linux/security.h b/include/linux/security.h
index c35ea0ffccd9..50db3d5d1608 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -291,6 +291,7 @@ int security_sb_alloc(struct super_block *sb);
void security_sb_free(struct super_block *sb);
void security_free_mnt_opts(void **mnt_opts);
int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
+int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
int security_sb_remount(struct super_block *sb, void *mnt_opts);
int security_sb_kern_mount(struct super_block *sb);
int security_sb_show_options(struct seq_file *m, struct super_block *sb);
@@ -635,6 +636,13 @@ static inline int security_sb_remount(struct super_block *sb,
return 0;
}

+static inline int security_sb_mnt_opts_compat(struct super_block *sb,
+ void *mnt_opts)
+{
+ return 0;
+}
+
+
static inline int security_sb_kern_mount(struct super_block *sb)
{
return 0;
diff --git a/security/security.c b/security/security.c
index 7b09cfbae94f..56cf5563efde 100644
--- a/security/security.c
+++ b/security/security.c
@@ -890,6 +890,13 @@ int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
}
EXPORT_SYMBOL(security_sb_eat_lsm_opts);

+int security_sb_mnt_opts_compat(struct super_block *sb,
+ void *mnt_opts)
+{
+ return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts);
+}
+EXPORT_SYMBOL(security_sb_mnt_opts_compat);
+
int security_sb_remount(struct super_block *sb,
void *mnt_opts)
{
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 644b17ec9e63..afee3a222a0e 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2656,6 +2656,61 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
return rc;
}

+static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
+{
+ struct selinux_mnt_opts *opts = mnt_opts;
+ struct superblock_security_struct *sbsec = sb->s_security;
+ u32 sid;
+ int rc;
+
+ /*
+ * Superblock not initialized (i.e. no options) - reject if any
+ * options specified, otherwise accept.
+ */
+ if (!(sbsec->flags & SE_SBINITIALIZED))
+ return opts ? 1 : 0;
+
+ /*
+ * Superblock initialized and no options specified - reject if
+ * superblock has any options set, otherwise accept.
+ */
+ if (!opts)
+ return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
+
+ if (opts->fscontext) {
+ rc = parse_sid(sb, opts->fscontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
+ return 1;
+ }
+ if (opts->context) {
+ rc = parse_sid(sb, opts->context, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
+ return 1;
+ }
+ if (opts->rootcontext) {
+ struct inode_security_struct *root_isec;
+
+ root_isec = backing_inode_security(sb->s_root);
+ rc = parse_sid(sb, opts->rootcontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
+ return 1;
+ }
+ if (opts->defcontext) {
+ rc = parse_sid(sb, opts->defcontext, &sid);
+ if (rc)
+ return 1;
+ if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
+ return 1;
+ }
+ return 0;
+}
+
static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
{
struct selinux_mnt_opts *opts = mnt_opts;
@@ -6984,6 +7039,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {

LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
+ LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
--
2.27.0

2021-03-04 06:34:27

by Anna Schumaker

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

Hi Casey,

On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
<[email protected]> wrote:
>
> From: Olga Kornievskaia <[email protected]>
>
> Add a new hook that takes an existing super block and a new mount
> with new options and determines if new options confict with an
> existing mount or not.
>
> A filesystem can use this new hook to determine if it can share
> the an existing superblock with a new superblock for the new mount.
>
> Signed-off-by: Olga Kornievskaia <[email protected]>

Do you have any other thoughts on this patch? I'm also wondering how
you want to handle sending it upstream. I'm happy to take it through
the NFS tree (with an acked-by) for a 5.12-rc with Olga's bugfix
patches, but if you have other thoughts or plans then let me know!

Thanks,
Anna

> ---
> include/linux/lsm_hook_defs.h | 1 +
> include/linux/lsm_hooks.h | 6 ++++
> include/linux/security.h | 8 +++++
> security/security.c | 7 +++++
> security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
> 5 files changed, 78 insertions(+)
>
> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> index 7aaa753b8608..1b12a5266a51 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -62,6 +62,7 @@ LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb)
> LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
> LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
> LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
> +LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
> LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
> LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
> LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index a19adef1f088..0de8eb2ea547 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -142,6 +142,12 @@
> * @orig the original mount data copied from userspace.
> * @copy copied data which will be passed to the security module.
> * Returns 0 if the copy was successful.
> + * @sb_mnt_opts_compat:
> + * Determine if the new mount options in @mnt_opts are allowed given
> + * the existing mounted filesystem at @sb.
> + * @sb superblock being compared
> + * @mnt_opts new mount options
> + * Return 0 if options are compatible.
> * @sb_remount:
> * Extracts security system specific mount options and verifies no changes
> * are being made to those options.
> diff --git a/include/linux/security.h b/include/linux/security.h
> index c35ea0ffccd9..50db3d5d1608 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -291,6 +291,7 @@ int security_sb_alloc(struct super_block *sb);
> void security_sb_free(struct super_block *sb);
> void security_free_mnt_opts(void **mnt_opts);
> int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
> +int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
> int security_sb_remount(struct super_block *sb, void *mnt_opts);
> int security_sb_kern_mount(struct super_block *sb);
> int security_sb_show_options(struct seq_file *m, struct super_block *sb);
> @@ -635,6 +636,13 @@ static inline int security_sb_remount(struct super_block *sb,
> return 0;
> }
>
> +static inline int security_sb_mnt_opts_compat(struct super_block *sb,
> + void *mnt_opts)
> +{
> + return 0;
> +}
> +
> +
> static inline int security_sb_kern_mount(struct super_block *sb)
> {
> return 0;
> diff --git a/security/security.c b/security/security.c
> index 7b09cfbae94f..56cf5563efde 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -890,6 +890,13 @@ int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
> }
> EXPORT_SYMBOL(security_sb_eat_lsm_opts);
>
> +int security_sb_mnt_opts_compat(struct super_block *sb,
> + void *mnt_opts)
> +{
> + return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts);
> +}
> +EXPORT_SYMBOL(security_sb_mnt_opts_compat);
> +
> int security_sb_remount(struct super_block *sb,
> void *mnt_opts)
> {
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 644b17ec9e63..afee3a222a0e 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -2656,6 +2656,61 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
> return rc;
> }
>
> +static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
> +{
> + struct selinux_mnt_opts *opts = mnt_opts;
> + struct superblock_security_struct *sbsec = sb->s_security;
> + u32 sid;
> + int rc;
> +
> + /*
> + * Superblock not initialized (i.e. no options) - reject if any
> + * options specified, otherwise accept.
> + */
> + if (!(sbsec->flags & SE_SBINITIALIZED))
> + return opts ? 1 : 0;
> +
> + /*
> + * Superblock initialized and no options specified - reject if
> + * superblock has any options set, otherwise accept.
> + */
> + if (!opts)
> + return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
> +
> + if (opts->fscontext) {
> + rc = parse_sid(sb, opts->fscontext, &sid);
> + if (rc)
> + return 1;
> + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
> + return 1;
> + }
> + if (opts->context) {
> + rc = parse_sid(sb, opts->context, &sid);
> + if (rc)
> + return 1;
> + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
> + return 1;
> + }
> + if (opts->rootcontext) {
> + struct inode_security_struct *root_isec;
> +
> + root_isec = backing_inode_security(sb->s_root);
> + rc = parse_sid(sb, opts->rootcontext, &sid);
> + if (rc)
> + return 1;
> + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
> + return 1;
> + }
> + if (opts->defcontext) {
> + rc = parse_sid(sb, opts->defcontext, &sid);
> + if (rc)
> + return 1;
> + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
> + return 1;
> + }
> + return 0;
> +}
> +
> static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
> {
> struct selinux_mnt_opts *opts = mnt_opts;
> @@ -6984,6 +7039,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
>
> LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
> LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
> + LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
> LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
> LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
> LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
> --
> 2.27.0
>

2021-03-04 07:48:38

by Casey Schaufler

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> Hi Casey,
>
> On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> <[email protected]> wrote:
>> From: Olga Kornievskaia <[email protected]>
>>
>> Add a new hook that takes an existing super block and a new mount
>> with new options and determines if new options confict with an
>> existing mount or not.
>>
>> A filesystem can use this new hook to determine if it can share
>> the an existing superblock with a new superblock for the new mount.
>>
>> Signed-off-by: Olga Kornievskaia <[email protected]>
> Do you have any other thoughts on this patch? I'm also wondering how
> you want to handle sending it upstream.

James Morris is the maintainer for the security sub-system,
so you'll want to send this through him. He will want you to
have an ACK from Paul Moore, who is the SELinux maintainer.

> I'm happy to take it through
> the NFS tree (with an acked-by) for a 5.12-rc with Olga's bugfix
> patches, but if you have other thoughts or plans then let me know!
>
> Thanks,
> Anna
>
>> ---
>> include/linux/lsm_hook_defs.h | 1 +
>> include/linux/lsm_hooks.h | 6 ++++
>> include/linux/security.h | 8 +++++
>> security/security.c | 7 +++++
>> security/selinux/hooks.c | 56 +++++++++++++++++++++++++++++++++++
>> 5 files changed, 78 insertions(+)
>>
>> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
>> index 7aaa753b8608..1b12a5266a51 100644
>> --- a/include/linux/lsm_hook_defs.h
>> +++ b/include/linux/lsm_hook_defs.h
>> @@ -62,6 +62,7 @@ LSM_HOOK(int, 0, sb_alloc_security, struct super_block *sb)
>> LSM_HOOK(void, LSM_RET_VOID, sb_free_security, struct super_block *sb)
>> LSM_HOOK(void, LSM_RET_VOID, sb_free_mnt_opts, void *mnt_opts)
>> LSM_HOOK(int, 0, sb_eat_lsm_opts, char *orig, void **mnt_opts)
>> +LSM_HOOK(int, 0, sb_mnt_opts_compat, struct super_block *sb, void *mnt_opts)
>> LSM_HOOK(int, 0, sb_remount, struct super_block *sb, void *mnt_opts)
>> LSM_HOOK(int, 0, sb_kern_mount, struct super_block *sb)
>> LSM_HOOK(int, 0, sb_show_options, struct seq_file *m, struct super_block *sb)
>> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
>> index a19adef1f088..0de8eb2ea547 100644
>> --- a/include/linux/lsm_hooks.h
>> +++ b/include/linux/lsm_hooks.h
>> @@ -142,6 +142,12 @@
>> * @orig the original mount data copied from userspace.
>> * @copy copied data which will be passed to the security module.
>> * Returns 0 if the copy was successful.
>> + * @sb_mnt_opts_compat:
>> + * Determine if the new mount options in @mnt_opts are allowed given
>> + * the existing mounted filesystem at @sb.
>> + * @sb superblock being compared
>> + * @mnt_opts new mount options
>> + * Return 0 if options are compatible.
>> * @sb_remount:
>> * Extracts security system specific mount options and verifies no changes
>> * are being made to those options.
>> diff --git a/include/linux/security.h b/include/linux/security.h
>> index c35ea0ffccd9..50db3d5d1608 100644
>> --- a/include/linux/security.h
>> +++ b/include/linux/security.h
>> @@ -291,6 +291,7 @@ int security_sb_alloc(struct super_block *sb);
>> void security_sb_free(struct super_block *sb);
>> void security_free_mnt_opts(void **mnt_opts);
>> int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
>> +int security_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts);
>> int security_sb_remount(struct super_block *sb, void *mnt_opts);
>> int security_sb_kern_mount(struct super_block *sb);
>> int security_sb_show_options(struct seq_file *m, struct super_block *sb);
>> @@ -635,6 +636,13 @@ static inline int security_sb_remount(struct super_block *sb,
>> return 0;
>> }
>>
>> +static inline int security_sb_mnt_opts_compat(struct super_block *sb,
>> + void *mnt_opts)
>> +{
>> + return 0;
>> +}
>> +
>> +
>> static inline int security_sb_kern_mount(struct super_block *sb)
>> {
>> return 0;
>> diff --git a/security/security.c b/security/security.c
>> index 7b09cfbae94f..56cf5563efde 100644
>> --- a/security/security.c
>> +++ b/security/security.c
>> @@ -890,6 +890,13 @@ int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
>> }
>> EXPORT_SYMBOL(security_sb_eat_lsm_opts);
>>
>> +int security_sb_mnt_opts_compat(struct super_block *sb,
>> + void *mnt_opts)
>> +{
>> + return call_int_hook(sb_mnt_opts_compat, 0, sb, mnt_opts);
>> +}
>> +EXPORT_SYMBOL(security_sb_mnt_opts_compat);
>> +
>> int security_sb_remount(struct super_block *sb,
>> void *mnt_opts)
>> {
>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
>> index 644b17ec9e63..afee3a222a0e 100644
>> --- a/security/selinux/hooks.c
>> +++ b/security/selinux/hooks.c
>> @@ -2656,6 +2656,61 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
>> return rc;
>> }
>>
>> +static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
>> +{
>> + struct selinux_mnt_opts *opts = mnt_opts;
>> + struct superblock_security_struct *sbsec = sb->s_security;
>> + u32 sid;
>> + int rc;
>> +
>> + /*
>> + * Superblock not initialized (i.e. no options) - reject if any
>> + * options specified, otherwise accept.
>> + */
>> + if (!(sbsec->flags & SE_SBINITIALIZED))
>> + return opts ? 1 : 0;
>> +
>> + /*
>> + * Superblock initialized and no options specified - reject if
>> + * superblock has any options set, otherwise accept.
>> + */
>> + if (!opts)
>> + return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
>> +
>> + if (opts->fscontext) {
>> + rc = parse_sid(sb, opts->fscontext, &sid);
>> + if (rc)
>> + return 1;
>> + if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
>> + return 1;
>> + }
>> + if (opts->context) {
>> + rc = parse_sid(sb, opts->context, &sid);
>> + if (rc)
>> + return 1;
>> + if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
>> + return 1;
>> + }
>> + if (opts->rootcontext) {
>> + struct inode_security_struct *root_isec;
>> +
>> + root_isec = backing_inode_security(sb->s_root);
>> + rc = parse_sid(sb, opts->rootcontext, &sid);
>> + if (rc)
>> + return 1;
>> + if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
>> + return 1;
>> + }
>> + if (opts->defcontext) {
>> + rc = parse_sid(sb, opts->defcontext, &sid);
>> + if (rc)
>> + return 1;
>> + if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
>> + return 1;
>> + }
>> + return 0;
>> +}
>> +
>> static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
>> {
>> struct selinux_mnt_opts *opts = mnt_opts;
>> @@ -6984,6 +7039,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
>>
>> LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
>> LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
>> + LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
>> LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
>> LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
>> LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
>> --
>> 2.27.0
>>

2021-03-05 01:34:10

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > Hi Casey,
> >
> > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > <[email protected]> wrote:
> >> From: Olga Kornievskaia <[email protected]>
> >>
> >> Add a new hook that takes an existing super block and a new mount
> >> with new options and determines if new options confict with an
> >> existing mount or not.
> >>
> >> A filesystem can use this new hook to determine if it can share
> >> the an existing superblock with a new superblock for the new mount.
> >>
> >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > Do you have any other thoughts on this patch? I'm also wondering how
> > you want to handle sending it upstream.
>
> James Morris is the maintainer for the security sub-system,
> so you'll want to send this through him. He will want you to
> have an ACK from Paul Moore, who is the SELinux maintainer.

In the past I've pulled patches such as this (new LSM hook, with only
a SELinux implementation of the new hook) in via the selinux/next tree
after the other LSMs have ACK'd the new hook. This helps limit merge
problems with other SELinux changes and allows us (the SELinux folks)
to include it in the ongoing testing that we do during the -rcX
releases.

So Anna, if you or anyone else on the NFS side of the house want to
add your ACKs/REVIEWs/etc. please do so as I don't like merging
patches that cross subsystem boundaries without having all the
associated ACKs. Casey, James, and other LSM folks please do the
same.

--
paul moore
http://www.paul-moore.com

2021-03-12 15:47:06

by Anna Schumaker

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
>
> On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > Hi Casey,
> > >
> > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > <[email protected]> wrote:
> > >> From: Olga Kornievskaia <[email protected]>
> > >>
> > >> Add a new hook that takes an existing super block and a new mount
> > >> with new options and determines if new options confict with an
> > >> existing mount or not.
> > >>
> > >> A filesystem can use this new hook to determine if it can share
> > >> the an existing superblock with a new superblock for the new mount.
> > >>
> > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > Do you have any other thoughts on this patch? I'm also wondering how
> > > you want to handle sending it upstream.
> >
> > James Morris is the maintainer for the security sub-system,
> > so you'll want to send this through him. He will want you to
> > have an ACK from Paul Moore, who is the SELinux maintainer.
>
> In the past I've pulled patches such as this (new LSM hook, with only
> a SELinux implementation of the new hook) in via the selinux/next tree
> after the other LSMs have ACK'd the new hook. This helps limit merge
> problems with other SELinux changes and allows us (the SELinux folks)
> to include it in the ongoing testing that we do during the -rcX
> releases.
>
> So Anna, if you or anyone else on the NFS side of the house want to
> add your ACKs/REVIEWs/etc. please do so as I don't like merging
> patches that cross subsystem boundaries without having all the
> associated ACKs. Casey, James, and other LSM folks please do the
> same.

Sure:
Acked-by: Anna Schumaker <[email protected]>

Are you also going to take patch 3/3 that uses the new hook, or should
that go through the NFS tree? Patch 2/3 is a cleanup that can go
through the NFS tree.

Anna

>
> --
> paul moore
> http://www.paul-moore.com

2021-03-12 21:58:24

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Fri, Mar 12, 2021 at 10:45 AM Anna Schumaker
<[email protected]> wrote:
> On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
> > On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > > Hi Casey,
> > > >
> > > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > > <[email protected]> wrote:
> > > >> From: Olga Kornievskaia <[email protected]>
> > > >>
> > > >> Add a new hook that takes an existing super block and a new mount
> > > >> with new options and determines if new options confict with an
> > > >> existing mount or not.
> > > >>
> > > >> A filesystem can use this new hook to determine if it can share
> > > >> the an existing superblock with a new superblock for the new mount.
> > > >>
> > > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > > Do you have any other thoughts on this patch? I'm also wondering how
> > > > you want to handle sending it upstream.
> > >
> > > James Morris is the maintainer for the security sub-system,
> > > so you'll want to send this through him. He will want you to
> > > have an ACK from Paul Moore, who is the SELinux maintainer.
> >
> > In the past I've pulled patches such as this (new LSM hook, with only
> > a SELinux implementation of the new hook) in via the selinux/next tree
> > after the other LSMs have ACK'd the new hook. This helps limit merge
> > problems with other SELinux changes and allows us (the SELinux folks)
> > to include it in the ongoing testing that we do during the -rcX
> > releases.
> >
> > So Anna, if you or anyone else on the NFS side of the house want to
> > add your ACKs/REVIEWs/etc. please do so as I don't like merging
> > patches that cross subsystem boundaries without having all the
> > associated ACKs. Casey, James, and other LSM folks please do the
> > same.
>
> Sure:
> Acked-by: Anna Schumaker <[email protected]>
>
> Are you also going to take patch 3/3 that uses the new hook, or should
> that go through the NFS tree? Patch 2/3 is a cleanup that can go
> through the NFS tree.

Generally when patches are posted as patchsets I would apply the whole
patchset assuming they patches were all good, however it does seem
like patch 2/3 is not strictly related to the other two? That said,
as long as your ACK applies to all three patches in the patchset I
have no problem applying all of them to the selinux/next tree once
some of the other LSM maintainers provide their ACKs (while there may
only a SELinux implementation of the hook at the moment, we need to
make sure the other LSMs are okay with the basic hook concept).

Also, did the v4 posting only include patch 1/3? I see v3 postings
for the other two patches, but the only v4 patch I see is 1/3 ... ?

--
paul moore
http://www.paul-moore.com

2021-03-12 22:36:16

by Olga Kornievskaia

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Fri, Mar 12, 2021 at 4:55 PM Paul Moore <[email protected]> wrote:
>
> On Fri, Mar 12, 2021 at 10:45 AM Anna Schumaker
> <[email protected]> wrote:
> > On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
> > > On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > > > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > > > Hi Casey,
> > > > >
> > > > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > > > <[email protected]> wrote:
> > > > >> From: Olga Kornievskaia <[email protected]>
> > > > >>
> > > > >> Add a new hook that takes an existing super block and a new mount
> > > > >> with new options and determines if new options confict with an
> > > > >> existing mount or not.
> > > > >>
> > > > >> A filesystem can use this new hook to determine if it can share
> > > > >> the an existing superblock with a new superblock for the new mount.
> > > > >>
> > > > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > > > Do you have any other thoughts on this patch? I'm also wondering how
> > > > > you want to handle sending it upstream.
> > > >
> > > > James Morris is the maintainer for the security sub-system,
> > > > so you'll want to send this through him. He will want you to
> > > > have an ACK from Paul Moore, who is the SELinux maintainer.
> > >
> > > In the past I've pulled patches such as this (new LSM hook, with only
> > > a SELinux implementation of the new hook) in via the selinux/next tree
> > > after the other LSMs have ACK'd the new hook. This helps limit merge
> > > problems with other SELinux changes and allows us (the SELinux folks)
> > > to include it in the ongoing testing that we do during the -rcX
> > > releases.
> > >
> > > So Anna, if you or anyone else on the NFS side of the house want to
> > > add your ACKs/REVIEWs/etc. please do so as I don't like merging
> > > patches that cross subsystem boundaries without having all the
> > > associated ACKs. Casey, James, and other LSM folks please do the
> > > same.
> >
> > Sure:
> > Acked-by: Anna Schumaker <[email protected]>
> >
> > Are you also going to take patch 3/3 that uses the new hook, or should
> > that go through the NFS tree? Patch 2/3 is a cleanup that can go
> > through the NFS tree.
>
> Generally when patches are posted as patchsets I would apply the whole
> patchset assuming they patches were all good, however it does seem
> like patch 2/3 is not strictly related to the other two? That said,
> as long as your ACK applies to all three patches in the patchset I
> have no problem applying all of them to the selinux/next tree once
> some of the other LSM maintainers provide their ACKs (while there may
> only a SELinux implementation of the hook at the moment, we need to
> make sure the other LSMs are okay with the basic hook concept).
>
> Also, did the v4 posting only include patch 1/3? I see v3 postings
> for the other two patches, but the only v4 patch I see is 1/3 ... ?

I didn't not repost patches that didn't change.

>
> --
> paul moore
> http://www.paul-moore.com

2021-03-15 01:45:16

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Fri, Mar 12, 2021 at 5:35 PM Olga Kornievskaia
<[email protected]> wrote:
> On Fri, Mar 12, 2021 at 4:55 PM Paul Moore <[email protected]> wrote:
> >
> > On Fri, Mar 12, 2021 at 10:45 AM Anna Schumaker
> > <[email protected]> wrote:
> > > On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
> > > > On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > > > > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > > > > Hi Casey,
> > > > > >
> > > > > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > > > > <[email protected]> wrote:
> > > > > >> From: Olga Kornievskaia <[email protected]>
> > > > > >>
> > > > > >> Add a new hook that takes an existing super block and a new mount
> > > > > >> with new options and determines if new options confict with an
> > > > > >> existing mount or not.
> > > > > >>
> > > > > >> A filesystem can use this new hook to determine if it can share
> > > > > >> the an existing superblock with a new superblock for the new mount.
> > > > > >>
> > > > > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > > > > Do you have any other thoughts on this patch? I'm also wondering how
> > > > > > you want to handle sending it upstream.
> > > > >
> > > > > James Morris is the maintainer for the security sub-system,
> > > > > so you'll want to send this through him. He will want you to
> > > > > have an ACK from Paul Moore, who is the SELinux maintainer.
> > > >
> > > > In the past I've pulled patches such as this (new LSM hook, with only
> > > > a SELinux implementation of the new hook) in via the selinux/next tree
> > > > after the other LSMs have ACK'd the new hook. This helps limit merge
> > > > problems with other SELinux changes and allows us (the SELinux folks)
> > > > to include it in the ongoing testing that we do during the -rcX
> > > > releases.
> > > >
> > > > So Anna, if you or anyone else on the NFS side of the house want to
> > > > add your ACKs/REVIEWs/etc. please do so as I don't like merging
> > > > patches that cross subsystem boundaries without having all the
> > > > associated ACKs. Casey, James, and other LSM folks please do the
> > > > same.
> > >
> > > Sure:
> > > Acked-by: Anna Schumaker <[email protected]>
> > >
> > > Are you also going to take patch 3/3 that uses the new hook, or should
> > > that go through the NFS tree? Patch 2/3 is a cleanup that can go
> > > through the NFS tree.
> >
> > Generally when patches are posted as patchsets I would apply the whole
> > patchset assuming they patches were all good, however it does seem
> > like patch 2/3 is not strictly related to the other two? That said,
> > as long as your ACK applies to all three patches in the patchset I
> > have no problem applying all of them to the selinux/next tree once
> > some of the other LSM maintainers provide their ACKs (while there may
> > only a SELinux implementation of the hook at the moment, we need to
> > make sure the other LSMs are okay with the basic hook concept).
> >
> > Also, did the v4 posting only include patch 1/3? I see v3 postings
> > for the other two patches, but the only v4 patch I see is 1/3 ... ?
>
> I didn't not repost patches that didn't change.

Okay, so I'm guessing that means path 2/3 and 3/3 didn't change?

While I suppose there are cases where people do not do this, it has
been my experience that if someone posts a patchset and some portion
of the patchset changes, due to feedback or other factors, the entire
patchset is reposted under the new version number. If nothing else
this helps ensure people are always looking at the latest draft of a
particular patch instead of having to dig through the list to
determine which patch is the most recent.

--
paul moore
http://www.paul-moore.com

2021-03-15 15:32:49

by Olga Kornievskaia

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Sun, Mar 14, 2021 at 9:44 PM Paul Moore <[email protected]> wrote:
>
> On Fri, Mar 12, 2021 at 5:35 PM Olga Kornievskaia
> <[email protected]> wrote:
> > On Fri, Mar 12, 2021 at 4:55 PM Paul Moore <[email protected]> wrote:
> > >
> > > On Fri, Mar 12, 2021 at 10:45 AM Anna Schumaker
> > > <[email protected]> wrote:
> > > > On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
> > > > > On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > > > > > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > > > > > Hi Casey,
> > > > > > >
> > > > > > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > > > > > <[email protected]> wrote:
> > > > > > >> From: Olga Kornievskaia <[email protected]>
> > > > > > >>
> > > > > > >> Add a new hook that takes an existing super block and a new mount
> > > > > > >> with new options and determines if new options confict with an
> > > > > > >> existing mount or not.
> > > > > > >>
> > > > > > >> A filesystem can use this new hook to determine if it can share
> > > > > > >> the an existing superblock with a new superblock for the new mount.
> > > > > > >>
> > > > > > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > > > > > Do you have any other thoughts on this patch? I'm also wondering how
> > > > > > > you want to handle sending it upstream.
> > > > > >
> > > > > > James Morris is the maintainer for the security sub-system,
> > > > > > so you'll want to send this through him. He will want you to
> > > > > > have an ACK from Paul Moore, who is the SELinux maintainer.
> > > > >
> > > > > In the past I've pulled patches such as this (new LSM hook, with only
> > > > > a SELinux implementation of the new hook) in via the selinux/next tree
> > > > > after the other LSMs have ACK'd the new hook. This helps limit merge
> > > > > problems with other SELinux changes and allows us (the SELinux folks)
> > > > > to include it in the ongoing testing that we do during the -rcX
> > > > > releases.
> > > > >
> > > > > So Anna, if you or anyone else on the NFS side of the house want to
> > > > > add your ACKs/REVIEWs/etc. please do so as I don't like merging
> > > > > patches that cross subsystem boundaries without having all the
> > > > > associated ACKs. Casey, James, and other LSM folks please do the
> > > > > same.
> > > >
> > > > Sure:
> > > > Acked-by: Anna Schumaker <[email protected]>
> > > >
> > > > Are you also going to take patch 3/3 that uses the new hook, or should
> > > > that go through the NFS tree? Patch 2/3 is a cleanup that can go
> > > > through the NFS tree.
> > >
> > > Generally when patches are posted as patchsets I would apply the whole
> > > patchset assuming they patches were all good, however it does seem
> > > like patch 2/3 is not strictly related to the other two? That said,
> > > as long as your ACK applies to all three patches in the patchset I
> > > have no problem applying all of them to the selinux/next tree once
> > > some of the other LSM maintainers provide their ACKs (while there may
> > > only a SELinux implementation of the hook at the moment, we need to
> > > make sure the other LSMs are okay with the basic hook concept).
> > >
> > > Also, did the v4 posting only include patch 1/3? I see v3 postings
> > > for the other two patches, but the only v4 patch I see is 1/3 ... ?
> >
> > I didn't not repost patches that didn't change.
>
> Okay, so I'm guessing that means path 2/3 and 3/3 didn't change?
>
> While I suppose there are cases where people do not do this, it has
> been my experience that if someone posts a patchset and some portion
> of the patchset changes, due to feedback or other factors, the entire
> patchset is reposted under the new version number. If nothing else
> this helps ensure people are always looking at the latest draft of a
> particular patch instead of having to dig through the list to
> determine which patch is the most recent.

Correct, patches 2&3 didn't change and selinux patch generated several
iterations. Would you like me to repost a series? I'm not sure what
I'm supposed to do at this point.

>
> --
> paul moore
> http://www.paul-moore.com

2021-03-15 16:17:46

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Mon, Mar 15, 2021 at 11:31 AM Olga Kornievskaia
<[email protected]> wrote:
> On Sun, Mar 14, 2021 at 9:44 PM Paul Moore <[email protected]> wrote:
> > On Fri, Mar 12, 2021 at 5:35 PM Olga Kornievskaia
> > <[email protected]> wrote:
> > > On Fri, Mar 12, 2021 at 4:55 PM Paul Moore <[email protected]> wrote:
> > > >
> > > > On Fri, Mar 12, 2021 at 10:45 AM Anna Schumaker
> > > > <[email protected]> wrote:
> > > > > On Thu, Mar 4, 2021 at 8:34 PM Paul Moore <[email protected]> wrote:
> > > > > > On Tue, Mar 2, 2021 at 10:53 PM Casey Schaufler <[email protected]> wrote:
> > > > > > > On 3/2/2021 10:20 AM, Anna Schumaker wrote:
> > > > > > > > Hi Casey,
> > > > > > > >
> > > > > > > > On Fri, Feb 26, 2021 at 10:40 PM Olga Kornievskaia
> > > > > > > > <olga.kornievskai[email protected]> wrote:
> > > > > > > >> From: Olga Kornievskaia <[email protected]>
> > > > > > > >>
> > > > > > > >> Add a new hook that takes an existing super block and a new mount
> > > > > > > >> with new options and determines if new options confict with an
> > > > > > > >> existing mount or not.
> > > > > > > >>
> > > > > > > >> A filesystem can use this new hook to determine if it can share
> > > > > > > >> the an existing superblock with a new superblock for the new mount.
> > > > > > > >>
> > > > > > > >> Signed-off-by: Olga Kornievskaia <[email protected]>
> > > > > > > > Do you have any other thoughts on this patch? I'm also wondering how
> > > > > > > > you want to handle sending it upstream.
> > > > > > >
> > > > > > > James Morris is the maintainer for the security sub-system,
> > > > > > > so you'll want to send this through him. He will want you to
> > > > > > > have an ACK from Paul Moore, who is the SELinux maintainer.
> > > > > >
> > > > > > In the past I've pulled patches such as this (new LSM hook, with only
> > > > > > a SELinux implementation of the new hook) in via the selinux/next tree
> > > > > > after the other LSMs have ACK'd the new hook. This helps limit merge
> > > > > > problems with other SELinux changes and allows us (the SELinux folks)
> > > > > > to include it in the ongoing testing that we do during the -rcX
> > > > > > releases.
> > > > > >
> > > > > > So Anna, if you or anyone else on the NFS side of the house want to
> > > > > > add your ACKs/REVIEWs/etc. please do so as I don't like merging
> > > > > > patches that cross subsystem boundaries without having all the
> > > > > > associated ACKs. Casey, James, and other LSM folks please do the
> > > > > > same.
> > > > >
> > > > > Sure:
> > > > > Acked-by: Anna Schumaker <[email protected]>
> > > > >
> > > > > Are you also going to take patch 3/3 that uses the new hook, or should
> > > > > that go through the NFS tree? Patch 2/3 is a cleanup that can go
> > > > > through the NFS tree.
> > > >
> > > > Generally when patches are posted as patchsets I would apply the whole
> > > > patchset assuming they patches were all good, however it does seem
> > > > like patch 2/3 is not strictly related to the other two? That said,
> > > > as long as your ACK applies to all three patches in the patchset I
> > > > have no problem applying all of them to the selinux/next tree once
> > > > some of the other LSM maintainers provide their ACKs (while there may
> > > > only a SELinux implementation of the hook at the moment, we need to
> > > > make sure the other LSMs are okay with the basic hook concept).
> > > >
> > > > Also, did the v4 posting only include patch 1/3? I see v3 postings
> > > > for the other two patches, but the only v4 patch I see is 1/3 ... ?
> > >
> > > I didn't not repost patches that didn't change.
> >
> > Okay, so I'm guessing that means path 2/3 and 3/3 didn't change?
> >
> > While I suppose there are cases where people do not do this, it has
> > been my experience that if someone posts a patchset and some portion
> > of the patchset changes, due to feedback or other factors, the entire
> > patchset is reposted under the new version number. If nothing else
> > this helps ensure people are always looking at the latest draft of a
> > particular patch instead of having to dig through the list to
> > determine which patch is the most recent.
>
> Correct, patches 2&3 didn't change and selinux patch generated several
> iterations. Would you like me to repost a series? I'm not sure what
> I'm supposed to do at this point.

As long as we are clear that the latest draft of patch 1/3 is to be
taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
from v3 of the patchset I don't think you need to do anything further.
The important bit is for the other LSM folks to ACK the new hook; if I
don't see anything from them, either positive or negative, I'll merge
it towards the end of this week or early next.

--
paul moore
http://www.paul-moore.com

2021-03-18 19:15:36

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Mon, Mar 15, 2021 at 12:15 PM Paul Moore <[email protected]> wrote:
> As long as we are clear that the latest draft of patch 1/3 is to be
> taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
> from v3 of the patchset I don't think you need to do anything further.
> The important bit is for the other LSM folks to ACK the new hook; if I
> don't see anything from them, either positive or negative, I'll merge
> it towards the end of this week or early next.

LSM folks, this is a reminder that if you want to object you've got
until Monday morning to do so :)

--
paul moore
http://www.paul-moore.com

2021-03-18 19:23:02

by Casey Schaufler

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On 3/18/2021 12:12 PM, Paul Moore wrote:
> On Mon, Mar 15, 2021 at 12:15 PM Paul Moore <[email protected]> wrote:
>> As long as we are clear that the latest draft of patch 1/3 is to be
>> taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
>> from v3 of the patchset I don't think you need to do anything further.
>> The important bit is for the other LSM folks to ACK the new hook; if I
>> don't see anything from them, either positive or negative, I'll merge
>> it towards the end of this week or early next.
> LSM folks, this is a reminder that if you want to object you've got
> until Monday morning to do so :)

No objections on my part. My comments have been addressed.

2021-03-18 22:56:10

by James Morris

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, 18 Mar 2021, Paul Moore wrote:

> On Mon, Mar 15, 2021 at 12:15 PM Paul Moore <[email protected]> wrote:
> > As long as we are clear that the latest draft of patch 1/3 is to be
> > taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
> > from v3 of the patchset I don't think you need to do anything further.
> > The important bit is for the other LSM folks to ACK the new hook; if I
> > don't see anything from them, either positive or negative, I'll merge
> > it towards the end of this week or early next.
>
> LSM folks, this is a reminder that if you want to object you've got
> until Monday morning to do so :)

I'm unclear on whether a new v5 patchset was being posted -- I assume not?

--
James Morris
<[email protected]>

2021-03-18 23:00:50

by Olga Kornievskaia

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, Mar 18, 2021 at 6:51 PM James Morris <[email protected]> wrote:
>
> On Thu, 18 Mar 2021, Paul Moore wrote:
>
> > On Mon, Mar 15, 2021 at 12:15 PM Paul Moore <[email protected]> wrote:
> > > As long as we are clear that the latest draft of patch 1/3 is to be
> > > taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
> > > from v3 of the patchset I don't think you need to do anything further.
> > > The important bit is for the other LSM folks to ACK the new hook; if I
> > > don't see anything from them, either positive or negative, I'll merge
> > > it towards the end of this week or early next.
> >
> > LSM folks, this is a reminder that if you want to object you've got
> > until Monday morning to do so :)
>
> I'm unclear on whether a new v5 patchset was being posted -- I assume not?

v4 addressed all the existing concerns/comments that were made. no new
version is planned unless somebody else has any more comments.

>
> --
> James Morris
> <[email protected]>
>

2021-03-22 18:57:48

by Paul Moore

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] [security] Add new hook to compare new mount to an existing mount

On Thu, Mar 18, 2021 at 3:12 PM Paul Moore <[email protected]> wrote:
> On Mon, Mar 15, 2021 at 12:15 PM Paul Moore <[email protected]> wrote:
> > As long as we are clear that the latest draft of patch 1/3 is to be
> > taken from the v4 patch{set} and patches 2/3 and 3/3 are to be taken
> > from v3 of the patchset I don't think you need to do anything further.
> > The important bit is for the other LSM folks to ACK the new hook; if I
> > don't see anything from them, either positive or negative, I'll merge
> > it towards the end of this week or early next.
>
> LSM folks, this is a reminder that if you want to object you've got
> until Monday morning to do so :)

Time is up, I just merged it into selinux/next ;)

Thanks everyone!

--
paul moore
http://www.paul-moore.com