linux.git/security/apparmor/include, branch v6.12.80

apparmor: fix race between freeing data and fs accessing it

2026-03-13T16:20:48+00:00

commit 8e135b8aee5a06c52a4347a5a6d51223c6f36ba3 upstream.

AppArmor was putting the reference to i_private data on its end after
removing the original entry from the file system. However the inode
can aand does live beyond that point and it is possible that some of
the fs call back functions will be invoked after the reference has
been put, which results in a race between freeing the data and
accessing it through the fs.

While the rawdata/loaddata is the most likely candidate to fail the
race, as it has the fewest references. If properly crafted it might be
possible to trigger a race for the other types stored in i_private.

Fix this by moving the put of i_private referenced data to the correct
place which is during inode eviction.

Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files")
Reported-by: Qualys Security Advisory 
Reviewed-by: Georgia Garcia 
Reviewed-by: Maxime Bélair 
Reviewed-by: Cengiz Can 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: fix race on rawdata dereference

2026-03-13T16:20:48+00:00

commit a0b7091c4de45a7325c8780e6934a894f92ac86b upstream.

There is a race condition that leads to a use-after-free situation:
because the rawdata inodes are not refcounted, an attacker can start
open()ing one of the rawdata files, and at the same time remove the
last reference to this rawdata (by removing the corresponding profile,
for example), which frees its struct aa_loaddata; as a result, when
seq_rawdata_open() is reached, i_private is a dangling pointer and
freed memory is accessed.

The rawdata inodes weren't refcounted to avoid a circular refcount and
were supposed to be held by the profile rawdata reference.  However
during profile removal there is a window where the vfs and profile
destruction race, resulting in the use after free.

Fix this by moving to a double refcount scheme. Where the profile
refcount on rawdata is used to break the circular dependency. Allowing
for freeing of the rawdata once all inode references to the rawdata
are put.

Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles")
Reported-by: Qualys Security Advisory 
Reviewed-by: Georgia Garcia 
Reviewed-by: Maxime Bélair 
Reviewed-by: Cengiz Can 
Tested-by: Salvatore Bonaccorso 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: fix differential encoding verification

2026-03-13T16:20:48+00:00

commit 39440b137546a3aa383cfdabc605fb73811b6093 upstream.

Differential encoding allows loops to be created if it is abused. To
prevent this the unpack should verify that a diff-encode chain
terminates.

Unfortunately the differential encode verification had two bugs.

1. it conflated states that had gone through check and already been
   marked, with states that were currently being checked and marked.
   This means that loops in the current chain being verified are treated
   as a chain that has already been verified.

2. the order bailout on already checked states compared current chain
   check iterators j,k instead of using the outer loop iterator i.
   Meaning a step backwards in states in the current chain verification
   was being mistaken for moving to an already verified state.

Move to a double mark scheme where already verified states get a
different mark, than the current chain being kept. This enables us
to also drop the backwards verification check that was the cause of
the second error as any already verified state is already marked.

Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding")
Reported-by: Qualys Security Advisory 
Tested-by: Salvatore Bonaccorso 
Reviewed-by: Georgia Garcia 
Reviewed-by: Cengiz Can 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: fix unprivileged local user can do privileged policy management

2026-03-13T16:20:48+00:00

commit 6601e13e82841879406bf9f369032656f441a425 upstream.

An unprivileged local user can load, replace, and remove profiles by
opening the apparmorfs interfaces, via a confused deputy attack, by
passing the opened fd to a privileged process, and getting the
privileged process to write to the interface.

This does require a privileged target that can be manipulated to do
the write for the unprivileged process, but once such access is
achieved full policy management is possible and all the possible
implications that implies: removing confinement, DoS of system or
target applications by denying all execution, by-passing the
unprivileged user namespace restriction, to exploiting kernel bugs for
a local privilege escalation.

The policy management interface can not have its permissions simply
changed from 0666 to 0600 because non-root processes need to be able
to load policy to different policy namespaces.

Instead ensure the task writing the interface has privileges that
are a subset of the task that opened the interface. This is already
done via policy for confined processes, but unconfined can delegate
access to the opened fd, by-passing the usual policy check.

Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files")
Reported-by: Qualys Security Advisory 
Tested-by: Salvatore Bonaccorso 
Reviewed-by: Georgia Garcia 
Reviewed-by: Cengiz Can 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: fix: limit the number of levels of policy namespaces

2026-03-13T16:20:47+00:00

commit 306039414932c80f8420695a24d4fe10c84ccfb2 upstream.

Currently the number of policy namespaces is not bounded relying on
the user namespace limit. However policy namespaces aren't strictly
tied to user namespaces and it is possible to create them and nest
them arbitrarily deep which can be used to exhaust system resource.

Hard cap policy namespaces to the same depth as user namespaces.

Fixes: c88d4c7b049e8 ("AppArmor: core policy routines")
Reported-by: Qualys Security Advisory 
Reviewed-by: Ryan Lee 
Reviewed-by: Cengiz Can 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: Fix & Optimize table creation from possibly unaligned memory

2026-03-04T12:20:40+00:00

[ Upstream commit 6fc367bfd4c8886e6b1742aabbd1c0bdc310db3a ]

Source blob may come from userspace and might be unaligned.
Try to optize the copying process by avoiding unaligned memory accesses.

- Added Fixes tag
- Added "Fix &" to description as this doesn't just optimize but fixes
        a potential unaligned memory access
Fixes: e6e8bf418850d ("apparmor: fix restricted endian type warnings for dfa unpack")
Signed-off-by: Helge Deller 
[jj: remove duplicate word "convert" in comment trigger checkpatch warning]
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: use the condition in AA_BUG_FMT even with debug disabled

2025-08-20T16:30:47+00:00

[ Upstream commit 67e370aa7f968f6a4f3573ed61a77b36d1b26475 ]

This follows the established practice and fixes a build failure for me:
security/apparmor/file.c: In function ‘__file_sock_perm’:
security/apparmor/file.c:544:24: error: unused variable ‘sock’ [-Werror=unused-variable]
  544 |         struct socket *sock = (struct socket *) file->private_data;
      |                        ^~~~

Signed-off-by: Mateusz Guzik 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: fix loop detection used in conflicting attachment resolution

2025-08-15T10:13:59+00:00

[ Upstream commit a88db916b8c77552f49f7d9f8744095ea01a268f ]

Conflicting attachment resolution is based on the number of states
traversed to reach an accepting state in the attachment DFA, accounting
for DFA loops traversed during the matching process. However, the loop
counting logic had multiple bugs:

 - The inc_wb_pos macro increments both position and length, but length
   is supposed to saturate upon hitting buffer capacity, instead of
   wrapping around.
 - If no revisited state is found when traversing the history, is_loop
   would still return true, as if there was a loop found the length of
   the history buffer, instead of returning false and signalling that
   no loop was found. As a result, the adjustment step of
   aa_dfa_leftmatch would sometimes produce negative counts with loop-
   free DFAs that traversed enough states.
 - The iteration in the is_loop for loop is supposed to stop before
   i = wb->len, so the conditional should be < instead of <=.

This patch fixes the above bugs as well as the following nits:
 - The count and size fields in struct match_workbuf were not used,
   so they can be removed.
 - The history buffer in match_workbuf semantically stores aa_state_t
   and not unsigned ints, even if aa_state_t is currently unsigned int.
 - The local variables in is_loop are counters, and thus should be
   unsigned ints instead of aa_state_t's.

Fixes: 21f606610502 ("apparmor: improve overlapping domain attachment resolution")

Signed-off-by: Ryan Lee 
Co-developed-by: John Johansen 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

apparmor: ensure WB_HISTORY_SIZE value is a power of 2

2025-08-15T10:13:59+00:00

[ Upstream commit 6c055e62560b958354625604293652753d82bcae ]

WB_HISTORY_SIZE was defined to be a value not a power of 2, despite a
comment in the declaration of struct match_workbuf stating it is and a
modular arithmetic usage in the inc_wb_pos macro assuming that it is. Bump
WB_HISTORY_SIZE's value up to 32 and add a BUILD_BUG_ON_NOT_POWER_OF_2
line to ensure that any future changes to the value of WB_HISTORY_SIZE
respect this requirement.

Fixes: 136db994852a ("apparmor: increase left match history buffer size")

Signed-off-by: Ryan Lee 
Signed-off-by: John Johansen 
Signed-off-by: Sasha Levin

lsm: infrastructure management of the sock security

2024-07-29T20:54:50+00:00

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

Acked-by: Paul Moore 
Reviewed-by: Kees Cook 
Reviewed-by: John Johansen 
Acked-by: Stephen Smalley 
Signed-off-by: Casey Schaufler 
[PM: subject tweak]
Signed-off-by: Paul Moore