<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/security, branch v7.2.4</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>smack: fix cred UAF in smack_file_send_sigiotask()</title>
<updated>2026-09-07T15:37:27+00:00</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2026-08-06T19:41:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b791401bf389a1546a830d2b381ca60fe94c7870'/>
<id>b791401bf389a1546a830d2b381ca60fe94c7870</id>
<content type='text'>
commit fedc88e38ce979a720cd2de042578cb5df3dc8de upstream.

When inspecting the credentials of another task, objective credentials
(-&gt;real_cred, accessed with __task_cred()) must always be used.

Accessing -&gt;cred on a non-current task is forbidden unless that task is
being created or destroyed; a task is allowed to change its own -&gt;cred
pointer with no synchronization, and changing -&gt;cred should only affect the
current syscall.

smack_file_send_sigiotask() was accessing both sets of credentials: First
tsk-&gt;cred, then __task_cred(tsk).

Fix it, always access the objective credentials here.

I have tested that this bug can lead to a KASAN-reported UAF of struct cred
in smack_file_send_sigiotask(), and that this fix prevents the race.

Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit fedc88e38ce979a720cd2de042578cb5df3dc8de upstream.

When inspecting the credentials of another task, objective credentials
(-&gt;real_cred, accessed with __task_cred()) must always be used.

Accessing -&gt;cred on a non-current task is forbidden unless that task is
being created or destroyed; a task is allowed to change its own -&gt;cred
pointer with no synchronization, and changing -&gt;cred should only affect the
current syscall.

smack_file_send_sigiotask() was accessing both sets of credentials: First
tsk-&gt;cred, then __task_cred(tsk).

Fix it, always access the objective credentials here.

I have tested that this bug can lead to a KASAN-reported UAF of struct cred
in smack_file_send_sigiotask(), and that this fix prevents the race.

Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation</title>
<updated>2026-09-07T15:36:59+00:00</updated>
<author>
<name>Günther Noack</name>
<email>gnoack@google.com</email>
</author>
<published>2026-08-13T09:31:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c3204aacbe8c07f9e87e3028f28ec6c166a1075'/>
<id>0c3204aacbe8c07f9e87e3028f28ec6c166a1075</id>
<content type='text'>
commit 672fa082d48b21e1fb62cdb184fee41513e53421 upstream.

Whiteout objects are used in the upper layer of an OverlayFS to
indicate that the file with this name does not exist in the unified
view, even if it is present in one of the lower layer file systems.

For the userspace implementations of OverlayFS (fuse-overlayfs),
whiteout objects can be created from userspace as well:

* mknod(2) with S_IFCHR and makedev(0, 0)
* renameat2(2) with RENAME_WHITEOUT,
  creating the whiteout in the old place of the moved file.

This commit guards whiteout creation in both of these cases with
LANDLOCK_ACCESS_FS_MAKE_REG.  Whiteout objects are *not* considered
character devices and are not bound to a driver.

LANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a
whiteout object: creating one is the only S_IFCHR creation that the VFS
exempts from CAP_MKNOD, so it is as unprivileged as creating a regular
file, while LANDLOCK_ACCESS_FS_MAKE_CHAR and
LANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that
expose a kernel interface [1].

For the mknod(2) case, introduce a Landlock erratum.  The creation of
whiteout objects through mknod(2) was previously guarded using
LANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using
LANDLOCK_ACCESS_FS_MAKE_REG.

For the renameat2(2) case, fix a bug: Before this commit, renameat2(2)
with RENAME_WHITEOUT would create a directory entry even when all
LANDLOCK_ACCESS_FS_MAKE_* rights were denied.

This does not affect normal renames within layered OverlayFS mounts:
When doing a regular rename() on a mounted fuse-overlayfs, it is the
fuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT,
and only the Landlock domain of that daemon is checked there.

Suggested-by: Christian Brauner &lt;brauner@kernel.org&gt;
Suggested-by: Mickaël Salaün &lt;mic@digikod.net&gt;
Cc: stable@vger.kernel.org
Fixes: cb2c7d1a1776 ("landlock: Support filesystem access-control")
Depends-on: 49c9e09d9610 ("landlock: Fix handling of disconnected directories")
Depends-on: fe72ce6710cb ("landlock: Add errata documentation section")
Signed-off-by: Günther Noack &lt;gnoack@google.com&gt;
Link: https://patch.msgid.link/20260720.chow9ohYie5b@digikod.net [1]
Link: https://patch.msgid.link/20260813093157.1436894-3-gnoack@google.com
[mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and
add link(2) to the user doc]
Signed-off-by: Mickaël Salaün &lt;mic@digikod.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 672fa082d48b21e1fb62cdb184fee41513e53421 upstream.

Whiteout objects are used in the upper layer of an OverlayFS to
indicate that the file with this name does not exist in the unified
view, even if it is present in one of the lower layer file systems.

For the userspace implementations of OverlayFS (fuse-overlayfs),
whiteout objects can be created from userspace as well:

* mknod(2) with S_IFCHR and makedev(0, 0)
* renameat2(2) with RENAME_WHITEOUT,
  creating the whiteout in the old place of the moved file.

This commit guards whiteout creation in both of these cases with
LANDLOCK_ACCESS_FS_MAKE_REG.  Whiteout objects are *not* considered
character devices and are not bound to a driver.

LANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a
whiteout object: creating one is the only S_IFCHR creation that the VFS
exempts from CAP_MKNOD, so it is as unprivileged as creating a regular
file, while LANDLOCK_ACCESS_FS_MAKE_CHAR and
LANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that
expose a kernel interface [1].

For the mknod(2) case, introduce a Landlock erratum.  The creation of
whiteout objects through mknod(2) was previously guarded using
LANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using
LANDLOCK_ACCESS_FS_MAKE_REG.

For the renameat2(2) case, fix a bug: Before this commit, renameat2(2)
with RENAME_WHITEOUT would create a directory entry even when all
LANDLOCK_ACCESS_FS_MAKE_* rights were denied.

This does not affect normal renames within layered OverlayFS mounts:
When doing a regular rename() on a mounted fuse-overlayfs, it is the
fuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT,
and only the Landlock domain of that daemon is checked there.

Suggested-by: Christian Brauner &lt;brauner@kernel.org&gt;
Suggested-by: Mickaël Salaün &lt;mic@digikod.net&gt;
Cc: stable@vger.kernel.org
Fixes: cb2c7d1a1776 ("landlock: Support filesystem access-control")
Depends-on: 49c9e09d9610 ("landlock: Fix handling of disconnected directories")
Depends-on: fe72ce6710cb ("landlock: Add errata documentation section")
Signed-off-by: Günther Noack &lt;gnoack@google.com&gt;
Link: https://patch.msgid.link/20260720.chow9ohYie5b@digikod.net [1]
Link: https://patch.msgid.link/20260813093157.1436894-3-gnoack@google.com
[mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and
add link(2) to the user doc]
Signed-off-by: Mickaël Salaün &lt;mic@digikod.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>apparmor: fix out-of-bounds write when null terminating a label vec</title>
<updated>2026-09-07T15:36:32+00:00</updated>
<author>
<name>Hyunwoo Kim</name>
<email>imv4bel@gmail.com</email>
</author>
<published>2026-08-10T09:51:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36bdd0b45ec3f4822832a56e9db8674c8450dfce'/>
<id>36bdd0b45ec3f4822832a56e9db8674c8450dfce</id>
<content type='text'>
commit 9f1e40193eef7f047e6b77cfb4b4cafdecd7a123 upstream.

aa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE
is passed. If the components are all distinct no duplicates are dropped,
dups is 0 and the terminator goes to vec[n], so the caller has to provide
room for n + 1 entries.

aa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len,
gfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but
vec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES
it uses the local array of LOCAL_VEC_ENTRIES pointers, above that it
allocates exactly len pointers. The terminator therefore lands one entry
past the end of the local array when len is LOCAL_VEC_ENTRIES, and one
entry past the end of the allocation when len is larger.

len comes from the number of "//&amp;" separated components in the label name
and label_count_strn_entries() does not bound it. An unprivileged task
reaches the parse by writing to /proc/self/attr/apparmor/current or through
lsm_set_self_attr(2), both of which go through do_setattr(), and the name
is parsed before the change_profile permission is checked.
The query_label() path behind the securityfs .access file, which is
mode 0666, performs no permission check at all. Every component has to
resolve to a loaded profile, so a system with policy loaded is required.

The other two VEC_FLAG_TERMINATE users work on a label vec that
aa_label_alloc() has already sized with "+ 1 for null terminator entry on
vec". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing
len + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of
the local array and into kzalloc().

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim &lt;imv4bel@gmail.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9f1e40193eef7f047e6b77cfb4b4cafdecd7a123 upstream.

aa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE
is passed. If the components are all distinct no duplicates are dropped,
dups is 0 and the terminator goes to vec[n], so the caller has to provide
room for n + 1 entries.

aa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len,
gfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but
vec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES
it uses the local array of LOCAL_VEC_ENTRIES pointers, above that it
allocates exactly len pointers. The terminator therefore lands one entry
past the end of the local array when len is LOCAL_VEC_ENTRIES, and one
entry past the end of the allocation when len is larger.

len comes from the number of "//&amp;" separated components in the label name
and label_count_strn_entries() does not bound it. An unprivileged task
reaches the parse by writing to /proc/self/attr/apparmor/current or through
lsm_set_self_attr(2), both of which go through do_setattr(), and the name
is parsed before the change_profile permission is checked.
The query_label() path behind the securityfs .access file, which is
mode 0666, performs no permission check at all. Every component has to
resolve to a loaded profile, so a system with policy loaded is required.

The other two VEC_FLAG_TERMINATE users work on a label vec that
aa_label_alloc() has already sized with "+ 1 for null terminator entry on
vec". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing
len + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of
the local array and into kzalloc().

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim &lt;imv4bel@gmail.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>apparmor: fix cred UAF caused by begin_current_label_crit_section()</title>
<updated>2026-09-07T15:36:32+00:00</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2026-08-06T15:55:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=580f777d6d9fd07fc034bd1aeba5c30fd48871a2'/>
<id>580f777d6d9fd07fc034bd1aeba5c30fd48871a2</id>
<content type='text'>
commit 3f4ae5fab613dca01d6a2a8210dd832e009fcf47 upstream.

AppArmor's begin_current_label_crit_section() is a scary function called
from lots of LSM hooks (in particular VFS/socket-related ones) that checks
if the label referenced by the current creds is marked FLAG_STALE, and if
so, attempts to use aa_replace_current_label() to replace the creds with an
updated version that uses a new label.

The first problem with this is that it would directly lead to UAF of
`struct cred` if anything in the kernel takes a pointer to the current
creds and accesses these past a security hook invocation that replaces
creds, like so:
```
const struct cred *cred = current_cred();
alloc_file_pseudo(...);
uid_t uid = cred-&gt;euid;
```
I don't know if anything in the kernel actually does this, but I think it
is very surprising that this pattern could lead to UAF.

The second problem is that things go wrong when aa_replace_current_label()
runs with overridden credentials. aa_replace_current_label() bails out if
`current_cred() != current_real_cred()` (mirroring the check in
proc_pid_attr_write()), but this check can't actually reliably detect
overridden credentials because the overridden creds can be the same as the
objective creds.

So in approximately the following scenario, things go wrong:

1. task begins with &lt;creds A&gt; (as both objective and subjective creds),
   with refcount=2
2. task grabs an extra reference on &lt;creds A&gt; for overriding
3. task calls override_creds(&lt;creds A&gt;), which returns a pointer to the old
   subjective creds (&lt;creds A&gt;)
4. task enters AppArmor LSM hook
5. AppArmor checks that objective/subjective creds are equal
6. AppArmor replaces both cred pointers with &lt;creds B&gt; and drops 2 refs on
   &lt;creds A&gt;
7. task leaves AppArmor LSM hook
8. task calls revert_creds(&lt;creds A&gt;)
9. now task-&gt;cred is &lt;creds A&gt; while task-&gt;real_cred is &lt;creds B&gt;, but the
   task_struct logically holds two references to &lt;creds B&gt;
10. another task drops the extra reference on &lt;creds A&gt; that was used for
    overriding, refcount drops to 0
11. now task-&gt;real_cred points to freed creds

At this point, any access to current_cred() will be UAF.

I have a test case where I run aa-disable on a profile while a process
using that profile is blocked on splice() from a FUSE passthrough file into
a full pipe; after the profile update, the pipe becomes empty, splice()
resumes, the credentials go out of sync, and a subsequent getuid() syscall
results in a KASAN UAF splat.

To fix this, instead of directly replacing creds, do it via task_work that
will run at the end of the current syscall. (The point in time at which the
cred replacement happens should have no correctness impact; it is just a
performance optimization to avoid unnecessarily touching the refcount of
the new label.)

Note that AppArmor still performs direct cred replacements in the
sb_pivotroot LSM hook after this change, and that direct cred replacements
can still happen in VFS -&gt;write() callbacks via proc_pid_attr_write().

There are two options for what to do with aa_dup_task_ctx(): Either
explicitly reset new-&gt;label_replacement_pending after the entire
aa_task_ctx has been copied, or switch to manually copying members over.
I am switching to manually copying members over because that should make
bugs more obvious.

Cc: stable@vger.kernel.org
Fixes: c75afcd153f6 ("AppArmor: contexts used in attaching policy to system objects")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3f4ae5fab613dca01d6a2a8210dd832e009fcf47 upstream.

AppArmor's begin_current_label_crit_section() is a scary function called
from lots of LSM hooks (in particular VFS/socket-related ones) that checks
if the label referenced by the current creds is marked FLAG_STALE, and if
so, attempts to use aa_replace_current_label() to replace the creds with an
updated version that uses a new label.

The first problem with this is that it would directly lead to UAF of
`struct cred` if anything in the kernel takes a pointer to the current
creds and accesses these past a security hook invocation that replaces
creds, like so:
```
const struct cred *cred = current_cred();
alloc_file_pseudo(...);
uid_t uid = cred-&gt;euid;
```
I don't know if anything in the kernel actually does this, but I think it
is very surprising that this pattern could lead to UAF.

The second problem is that things go wrong when aa_replace_current_label()
runs with overridden credentials. aa_replace_current_label() bails out if
`current_cred() != current_real_cred()` (mirroring the check in
proc_pid_attr_write()), but this check can't actually reliably detect
overridden credentials because the overridden creds can be the same as the
objective creds.

So in approximately the following scenario, things go wrong:

1. task begins with &lt;creds A&gt; (as both objective and subjective creds),
   with refcount=2
2. task grabs an extra reference on &lt;creds A&gt; for overriding
3. task calls override_creds(&lt;creds A&gt;), which returns a pointer to the old
   subjective creds (&lt;creds A&gt;)
4. task enters AppArmor LSM hook
5. AppArmor checks that objective/subjective creds are equal
6. AppArmor replaces both cred pointers with &lt;creds B&gt; and drops 2 refs on
   &lt;creds A&gt;
7. task leaves AppArmor LSM hook
8. task calls revert_creds(&lt;creds A&gt;)
9. now task-&gt;cred is &lt;creds A&gt; while task-&gt;real_cred is &lt;creds B&gt;, but the
   task_struct logically holds two references to &lt;creds B&gt;
10. another task drops the extra reference on &lt;creds A&gt; that was used for
    overriding, refcount drops to 0
11. now task-&gt;real_cred points to freed creds

At this point, any access to current_cred() will be UAF.

I have a test case where I run aa-disable on a profile while a process
using that profile is blocked on splice() from a FUSE passthrough file into
a full pipe; after the profile update, the pipe becomes empty, splice()
resumes, the credentials go out of sync, and a subsequent getuid() syscall
results in a KASAN UAF splat.

To fix this, instead of directly replacing creds, do it via task_work that
will run at the end of the current syscall. (The point in time at which the
cred replacement happens should have no correctness impact; it is just a
performance optimization to avoid unnecessarily touching the refcount of
the new label.)

Note that AppArmor still performs direct cred replacements in the
sb_pivotroot LSM hook after this change, and that direct cred replacements
can still happen in VFS -&gt;write() callbacks via proc_pid_attr_write().

There are two options for what to do with aa_dup_task_ctx(): Either
explicitly reset new-&gt;label_replacement_pending after the entire
aa_task_ctx has been copied, or switch to manually copying members over.
I am switching to manually copying members over because that should make
bugs more obvious.

Cc: stable@vger.kernel.org
Fixes: c75afcd153f6 ("AppArmor: contexts used in attaching policy to system objects")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: John Johansen &lt;john.johansen@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KEYS: trusted: Fix TPM teardown ordering</title>
<updated>2026-09-07T15:36:32+00:00</updated>
<author>
<name>Chengfeng Ye</name>
<email>nicoyip.dev@gmail.com</email>
</author>
<published>2026-08-10T23:56:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2f7541afbc57fe9d26769a22c31d8ce8790c9a19'/>
<id>2f7541afbc57fe9d26769a22c31d8ce8790c9a19</id>
<content type='text'>
commit 5e2d672280d97d83de43031d93761b12dadd7b8a upstream.

trusted_tpm_exit() drops the TPM chip reference and frees the digest
array before unregistering the trusted key type. key_type_lookup()
holds key_types_sem for reading until the key operation finishes, while
unregister_key_type() takes it for writing. It therefore provides the
synchronization point that must precede backend teardown.

The current order permits this interleaving:

  CPU 0                              CPU 1
  trusted_tpm_exit()                 key_type_lookup("trusted")
    put_device(&amp;chip-&gt;dev)             trusted_tpm_seal()
    kfree(digests)                       pcrlock()
    unregister_key_type()                  tpm_pcr_extend(..., digests)

CPU 1 can consequently dereference the freed digest array. The chip can
also be released before callbacks stop using it.

KASAN reported:

  BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200
  Read of size 2 at addr ffff88810872d000 by task poc/89
  Call Trace:
    tpm_pcr_extend+0x1f0/0x200
    pcrlock+0x42/0x70 [trusted]
    trusted_tpm_seal+0x1b6/0x570 [trusted]
    trusted_instantiate+0x293/0x340 [trusted]
    __key_instantiate_and_link+0xb2/0x2b0
    __key_create_or_update+0x61e/0xb50
    __do_sys_add_key+0x1b8/0x310
  Allocated by task 88:
    __kmalloc_noprof+0x1a7/0x490
    do_one_initcall+0xa1/0x390
    do_init_module+0x2df/0x840
  Freed by task 90:
    kfree+0x131/0x3c0
    trusted_tpm_exit+0x59/0xa0 [trusted]
    __do_sys_delete_module+0x346/0x510

Move unregister_key_type() before releasing either resource. This stops
new lookups and waits for in-flight key operations to finish before the
backend state is destroyed.

Fixes: 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()")
Cc: stable@vger.kernel.org
Signed-off-by: Chengfeng Ye &lt;nicoyip.dev@gmail.com&gt;
Link: https://lore.kernel.org/r/20260731140925.2973492-1-nicoyip.dev@gmail.com
Reviewed-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Tested-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5e2d672280d97d83de43031d93761b12dadd7b8a upstream.

trusted_tpm_exit() drops the TPM chip reference and frees the digest
array before unregistering the trusted key type. key_type_lookup()
holds key_types_sem for reading until the key operation finishes, while
unregister_key_type() takes it for writing. It therefore provides the
synchronization point that must precede backend teardown.

The current order permits this interleaving:

  CPU 0                              CPU 1
  trusted_tpm_exit()                 key_type_lookup("trusted")
    put_device(&amp;chip-&gt;dev)             trusted_tpm_seal()
    kfree(digests)                       pcrlock()
    unregister_key_type()                  tpm_pcr_extend(..., digests)

CPU 1 can consequently dereference the freed digest array. The chip can
also be released before callbacks stop using it.

KASAN reported:

  BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200
  Read of size 2 at addr ffff88810872d000 by task poc/89
  Call Trace:
    tpm_pcr_extend+0x1f0/0x200
    pcrlock+0x42/0x70 [trusted]
    trusted_tpm_seal+0x1b6/0x570 [trusted]
    trusted_instantiate+0x293/0x340 [trusted]
    __key_instantiate_and_link+0xb2/0x2b0
    __key_create_or_update+0x61e/0xb50
    __do_sys_add_key+0x1b8/0x310
  Allocated by task 88:
    __kmalloc_noprof+0x1a7/0x490
    do_one_initcall+0xa1/0x390
    do_init_module+0x2df/0x840
  Freed by task 90:
    kfree+0x131/0x3c0
    trusted_tpm_exit+0x59/0xa0 [trusted]
    __do_sys_delete_module+0x346/0x510

Move unregister_key_type() before releasing either resource. This stops
new lookups and waits for in-flight key operations to finish before the
backend state is destroyed.

Fixes: 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()")
Cc: stable@vger.kernel.org
Signed-off-by: Chengfeng Ye &lt;nicoyip.dev@gmail.com&gt;
Link: https://lore.kernel.org/r/20260731140925.2973492-1-nicoyip.dev@gmail.com
Reviewed-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Tested-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux</title>
<updated>2026-08-05T20:40:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-05T20:40:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c5096fec0c58a4f4d2475d4d88697c505800e50e'/>
<id>c5096fec0c58a4f4d2475d4d88697c505800e50e</id>
<content type='text'>
Pull selinux fixes from Paul Moore:

 - Continue to improve the validation of SELinux policies during load

 - Fix a SELinux regression caused by bpffs changes in v7.2-rc1

 - Fix a SELinux preformance regression caused by SELinux changes in
   v7.2-rc1

* tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: check level category sets once at load time
  selinux: require every boolean value to be defined
  selinux: reject an unclaimed class value in security_get_classes()
  selinux: require a class's permission values to cover its permission count
  selinux: do not cancel a policy conversion that never started
  selinux: bpf: check SBLABEL_MNT before isec init
  selinux: reject a class permission count below its inherited common
  selinux: reject a permission value exceeding the class permission count
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull selinux fixes from Paul Moore:

 - Continue to improve the validation of SELinux policies during load

 - Fix a SELinux regression caused by bpffs changes in v7.2-rc1

 - Fix a SELinux preformance regression caused by SELinux changes in
   v7.2-rc1

* tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: check level category sets once at load time
  selinux: require every boolean value to be defined
  selinux: reject an unclaimed class value in security_get_classes()
  selinux: require a class's permission values to cover its permission count
  selinux: do not cancel a policy conversion that never started
  selinux: bpf: check SBLABEL_MNT before isec init
  selinux: reject a class permission count below its inherited common
  selinux: reject a permission value exceeding the class permission count
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Instantiate file_truncate and path_truncate hooks</title>
<updated>2026-08-04T16:35:02+00:00</updated>
<author>
<name>Mimi Zohar</name>
<email>zohar@linux.ibm.com</email>
</author>
<published>2026-07-28T00:39:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b80bed5c871a80151351342c065579405ce77145'/>
<id>b80bed5c871a80151351342c065579405ce77145</id>
<content type='text'>
Instantiate the file_truncate and path_truncate LSM hooks to reset the
action cache flags (IMA_DONE_MASK) as soon as truncation is requested,
so the file, based on policy, is re-collected, re-measured, re-audited,
and re-appraised on next access.

Tested-by: Frederick Lawler &lt;fred@cloudflare.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Instantiate the file_truncate and path_truncate LSM hooks to reset the
action cache flags (IMA_DONE_MASK) as soon as truncation is requested,
so the file, based on policy, is re-collected, re-measured, re-audited,
and re-appraised on next access.

Tested-by: Frederick Lawler &lt;fred@cloudflare.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: fix out-of-bounds read in xattr_verify()</title>
<updated>2026-08-04T16:35:02+00:00</updated>
<author>
<name>Lincoln Wallace</name>
<email>locnnil0@gmail.com</email>
</author>
<published>2026-08-03T13:50:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5ff232d31106f45ac87c3b64e1d35a0667777797'/>
<id>5ff232d31106f45ac87c3b64e1d35a0667777797</id>
<content type='text'>
The digest-length check in xattr_verify() mixes int and size_t:

	if (xattr_len - sizeof(xattr_value-&gt;type) - hash_start &gt;=
			iint-&gt;ima_hash-&gt;length)

sizeof() yields size_t, so the usual arithmetic conversions promote
the whole left-hand side to unsigned 64-bit before the subtraction
runs. For a truncated xattr this underflows instead of going negative:
a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)
turns "1 - 1 - 1" into SIZE_MAX, which is trivially &gt;= ima_hash-&gt;length.
The check then passes and the following memcmp() reads
iint-&gt;ima_hash-&gt;length bytes starting past the end of the buffer
vfs_getxattr_alloc() allocated for it.

Nothing upstream clamps xattr_len back into a safe range first:
ima_get_hash_algo() only special-cases xattr_len &lt; 2 to pick a default
algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than
failing when no HMAC key is loaded, so a truncated security.ima value
reaches the length check as-is.

Rewrite the comparison so every operand stays a signed int and no
implicit conversion to size_t can occur.

Fixes: 3ea7a56067e6 ("ima: provide hash algo info in the xattr")
Cc: stable@vger.kernel.org
Signed-off-by: Lincoln Wallace &lt;locnnil0@gmail.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The digest-length check in xattr_verify() mixes int and size_t:

	if (xattr_len - sizeof(xattr_value-&gt;type) - hash_start &gt;=
			iint-&gt;ima_hash-&gt;length)

sizeof() yields size_t, so the usual arithmetic conversions promote
the whole left-hand side to unsigned 64-bit before the subtraction
runs. For a truncated xattr this underflows instead of going negative:
a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)
turns "1 - 1 - 1" into SIZE_MAX, which is trivially &gt;= ima_hash-&gt;length.
The check then passes and the following memcmp() reads
iint-&gt;ima_hash-&gt;length bytes starting past the end of the buffer
vfs_getxattr_alloc() allocated for it.

Nothing upstream clamps xattr_len back into a safe range first:
ima_get_hash_algo() only special-cases xattr_len &lt; 2 to pick a default
algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than
failing when no HMAC key is loaded, so a truncated security.ima value
reaches the length check as-is.

Rewrite the comparison so every operand stays a signed int and no
implicit conversion to size_t can occur.

Fixes: 3ea7a56067e6 ("ima: provide hash algo info in the xattr")
Cc: stable@vger.kernel.org
Signed-off-by: Lincoln Wallace &lt;locnnil0@gmail.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: check level category sets once at load time</title>
<updated>2026-08-04T14:57:46+00:00</updated>
<author>
<name>Stephen Smalley</name>
<email>stephen.smalley.work@gmail.com</email>
</author>
<published>2026-08-04T13:57:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9c1cc4a7f79275ef93746f6247685763b475bfb0'/>
<id>9c1cc4a7f79275ef93746f6247685763b475bfb0</id>
<content type='text'>
As reported by Jiri Vozar, commit 7edea6e8c8e8 ("selinux: beef up
isvalid checks") introduces a new loop in mls_level_isvalid() that
causes ~89-94% throughput regression in System V IPC message queue
operations (msgsnd/msgrcv).

Move the expensive part of the ebitmap checking to policy load time
instead as the reporter suggested.

Link: https://lore.kernel.org/selinux/CAMgFczCi2Z011dNf84Amc0Q-qnTt0+VUjWY+Y7zPyXdaH35Jvw@mail.gmail.com/
Fixes: 7edea6e8c8e8 ("selinux: beef up isvalid checks")
Reported-by: Jiri Vozar &lt;jvozar@redhat.com&gt;
Suggested-by: Jiri Vozar &lt;jvozar@redhat.com&gt;
Signed-off-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As reported by Jiri Vozar, commit 7edea6e8c8e8 ("selinux: beef up
isvalid checks") introduces a new loop in mls_level_isvalid() that
causes ~89-94% throughput regression in System V IPC message queue
operations (msgsnd/msgrcv).

Move the expensive part of the ebitmap checking to policy load time
instead as the reporter suggested.

Link: https://lore.kernel.org/selinux/CAMgFczCi2Z011dNf84Amc0Q-qnTt0+VUjWY+Y7zPyXdaH35Jvw@mail.gmail.com/
Fixes: 7edea6e8c8e8 ("selinux: beef up isvalid checks")
Reported-by: Jiri Vozar &lt;jvozar@redhat.com&gt;
Suggested-by: Jiri Vozar &lt;jvozar@redhat.com&gt;
Signed-off-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selinux: require every boolean value to be defined</title>
<updated>2026-08-03T20:03:57+00:00</updated>
<author>
<name>Bryam Vargas</name>
<email>hexlabsecurity@proton.me</email>
</author>
<published>2026-07-31T17:44:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a93d37a09b863810653f93d371fb197457d59deb'/>
<id>a93d37a09b863810653f93d371fb197457d59deb</id>
<content type='text'>
p_bools.nprim comes from the policy image independently of how many
booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at
value - 1, so a count larger than the values present leaves NULL entries.
Every user of that array then walks it by index and dereferences each
entry: cond_evaluate_expr() on the access-vector path,
security_get_bools() and security_get_bool_value() behind selinuxfs, and
security_set_bools(). A sparse class value is absorbed by
policydb_class_isvalid() and its siblings; booleans have no such
predicate, and no consumer that could use one.

Reject a boolean value that no boolean defines, once, where the array is
built. Conforming policies define every boolean they declare and are
unaffected.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Bryam Vargas &lt;hexlabsecurity@proton.me&gt;
Acked-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
p_bools.nprim comes from the policy image independently of how many
booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at
value - 1, so a count larger than the values present leaves NULL entries.
Every user of that array then walks it by index and dereferences each
entry: cond_evaluate_expr() on the access-vector path,
security_get_bools() and security_get_bool_value() behind selinuxfs, and
security_set_bools(). A sparse class value is absorbed by
policydb_class_isvalid() and its siblings; booleans have no such
predicate, and no consumer that could use one.

Reject a boolean value that no boolean defines, once, where the array is
built. Conforming policies define every boolean they declare and are
unaffected.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Bryam Vargas &lt;hexlabsecurity@proton.me&gt;
Acked-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
