kernel/linux.git/security/apparmor/include, branch v6.6.132

apparmor: fix race between freeing data and fs accessing it

2026-03-25T10:05:43+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 and 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

2026-03-25T10:05:43+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

2026-03-25T10:05:43+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

2026-03-25T10:05:43+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

2026-03-25T10:05:43+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: refcount the pdb

2026-03-04T12:20:24+00:00

[ Upstream commit 98b824ff8984fd523fc264fbb13208098ab09da3 ] With the move to permission tables the dfa is no longer a stand alone entity when used, needing a minimum of a permission table. However it still could be shared among different pdbs each using a different permission table. Instead of duping the permission table when sharing a pdb, add a refcount to the pdb so it can be easily shared. Reviewed-by: Georgia Garcia Signed-off-by: John Johansen Stable-dep-of: a4c9efa4dbad ("apparmor: make label_match return a consistent value") Signed-off-by: Sasha Levin

apparmor: use the condition in AA_BUG_FMT even with debug disabled

2025-08-28T14:28:28+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

2025-08-15T10:08:57+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

2025-08-15T10:08:57+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

ima: Avoid blocking in RCU read-side critical section

2024-07-11T10:49:18+00:00

commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua Acked-by: John Johansen Reviewed-by: Mimi Zohar Reviewed-by: Casey Schaufler [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman