CVE-2026-72455 apparmor: fix uninitialised pointer passed to audit_log_untrustedstring()
A bug in the Linux kernel AppArmor module causes a page fault and system crash when processing specific file paths.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72455?
CVE-2026-72455 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix uninitialised pointer passed to audit_log_untrustedstring()
Commit 4a134723f9f1 ("apparmor: move check for aa_null file to cover all cases") intrdouced a small bug, where path_name() may pass a potentially uninitialized *name to aa_audit_file() if the path->dentry had been replaced with aa_null.dentry earlier on. This can lead to page fault like one observed on 7.0.2 openSUSE Tumbleweed kernel:
[51692.242756] [ T24690] BUG: unable to handle page fault for address: 0000000f00000003 [51692.242762] [ T24690] #PF: supervisor read access in kernel mode [51692.242763] [ T24690] #PF: error_code(0x0000) - not-present page [51692.242765] [ T24690] PGD 0 P4D 0 [51692.242768] [ T24690] Oops: Oops: 0000 [#1] SMP NOPTI [51692.242772] [ T24690] CPU: 3 UID: 1020 PID: 24690 Comm: snap-confine Tainted: G O 7.0.2-1-default #1 PREEMPT(full) openSUSE Tumbleweed ab90b4c9940707f9cafa19bdad80b2cec52dbe51 [51692.242775] [ T24690] Tainted: [O]=OOT_MODULE [51692.242777] [ T24690] Hardware name: Framework Laptop 13 (AMD Ryzen 7040Series)/FRANMDCP05, BIOS 03.18 01/08/2026 [51692.242778] [ T24690] RIP: 0010:strlen+0x4/0x30 [51692.242783] [ T24690] Code: f7 75 ec 31 c0 e9 17 9f 00 ff 48 89 f8 e9 0f 9f 00 ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <80> 3f 00 74 18 48 89 f8 0f 1f 40 00 48 83 c0 01 80 38 00 75 f7 48 [51692.242785] [ T24690] RSP: 0018:ffffd015eb1e3608 EFLAGS: 00010282 [51692.242787] [ T24690] RAX: 0000000000000000 RBX: ffff89796198a360 RCX: 0000000000000000 [51692.242788] [ T24690] RDX: 00000000000000d1 RSI: 0000000f00000003 RDI: 0000000f00000003 [51692.242790] [ T24690] RBP: ffffffffb7ede090 R08: 00000000000005f5 R09: 0000000000000000 [51692.242791] [ T24690] R10: 0000000000000000 R11: 0000000000000000 R12: ffffd015eb1e3700 [51692.242792] [ T24690] R13: ffff8977a22bc380 R14: ffffffffb7ec5190 R15: ffff8977a0c8aa80 [51692.242794] [ T24690] FS: 0000000000000000(0000) GS:ffff897f640d8000(0000) knlGS:0000000000000000 [51692.242796] [ T24690] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [51692.242797] [ T24690] CR2: 0000000f00000003 CR3: 00000006ad15f000 CR4: 0000000000f50ef0 [51692.242799] [ T24690] PKRU: 55555554 [51692.242800] [ T24690] Call Trace: [51692.242802] [ T24690] <TASK> [51692.242804] [ T24690] audit_log_untrustedstring+0x1d/0x40 [51692.242811] [ T24690] common_lsm_audit+0x71/0x1d0 [51692.242816] [ T24690] aa_audit+0x5a/0x170 [51692.242819] [ T24690] aa_audit_file+0x18a/0x1b0 [51692.242825] [ T24690] path_name+0xd2/0x100 [51692.242829] [ T24690] profile_path_perm.part.0+0x58/0xb0 [51692.242832] [ T24690] aa_path_perm+0xef/0x150 [51692.242837] [ T24690] apparmor_file_open+0x153/0x2e0 [51692.242840] [ T24690] security_file_open+0x46/0xd0 [51692.242844] [ T24690] do_dentry_open+0xe9/0x4d0 [51692.242848] [ T24690] vfs_open+0x30/0x100
While here, initialise variables which are passed down to path_name().
Which versions are affected by CVE-2026-72455?
How do I fix CVE-2026-72455?
Apply the vendor's patch.
Is CVE-2026-72455 being exploited?
There is no known exploitation of CVE-2026-72455 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72455, DEBIAN-CVE-2026-72455, GHSA-r85g-hm8c-rxmx, UBUNTU-CVE-2026-72455.