In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix missing bounds check on DEFAULT table in verify_dfa()
The verify_dfa() function only checks DEFAULT_TABLE bounds when the state is not differentially encoded.
When the verification loop traverses the differential encoding chain, it reads k = DEFAULT_TABLE[j] and uses k as an array index without validation. A malformed DFA with DEFAULT_TABLE[j] >= state_count, therefore, causes both out-of-bounds reads and writes.
[ 57.179855] ================================================================== [ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660 [ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993
[ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy) [ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 57.181563] Call Trace: [ 57.181572] <TASK> [ 57.181577] dump_stack_lvl+0x5e/0x80 [ 57.181596] print_report+0xc8/0x270 [ 57.181605] ? verify_dfa+0x59a/0x660 [ 57.181608] kasan_report+0x118/0x150 [ 57.181620] ? verify_dfa+0x59a/0x660 [ 57.181623] verify_dfa+0x59a/0x660 [ 57.181627] aa_dfa_unpack+0x1610/0x1740 [ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470 [ 57.181640] unpack_pdb+0x86d/0x46b0 [ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181656] ? aa_unpack_nameX+0x1a8/0x300 [ 57.181659] aa_unpack+0x20b0/0x4c30 [ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181664] ? stack_depot_save_flags+0x33/0x700 [ 57.181681] ? kasan_save_track+0x4f/0x80 [ 57.181683] ? kasan_save_track+0x3e/0x80 [ 57.181686] ? __kasan_kmalloc+0x93/0xb0 [ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780 [ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130 [ 57.181697] ? policy_update+0x154/0x330 [ 57.181704] aa_replace_profiles+0x15a/0x1dd0 [ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780 [ 57.181712] ? aa_loaddata_alloc+0x77/0x140 [ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181717] ? _copy_from_user+0x2a/0x70 [ 57.181730] policy_update+0x17a/0x330 [ 57.181733] profile_replace+0x153/0x1a0 [ 57.181735] ? rw_verify_area+0x93/0x2d0 [ 57.181740] vfs_write+0x235/0xab0 [ 57.181745] ksys_write+0xb0/0x170 [ 57.181748] do_syscall_64+0x8e/0x660 [ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 57.181765] RIP: 0033:0x7f6192792eb2
Remove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE entries unconditionally.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Apr 2, 2026 | Apr 2, 2026 |
| Ubuntu | — | Upgrade linux-image-azureUpgrade linux-image-5.15.0-1109-azure-fipsUpgrade linux-image-azure-5.4Upgrade linux-image-6.8.0-1052-azure-fipsUpgrade linux-image-5.15.0-1109-azureUpgrade linux-image-xilinx-zynqmpUpgrade linux-image-5.15.0-1096-intel-iot-realtimeUpgrade linux-image-azure-lts-22.04Upgrade linux-image-azure-fips-5.15Upgrade linux-image-oem-24.04bUpgrade linux-image-bluefield-5.4Upgrade linux-image-5.4.0-1161-azureUpgrade linux-image-raspiUpgrade linux-image-oem-24.04Upgrade linux-image-6.17.0-1017-oemUpgrade linux-image-intel-iot-realtimeUpgrade linux-image-5.4.0-1116-bluefieldUpgrade linux-image-6.8.0-1029-xilinxUpgrade linux-image-5.15.0-1110-azureUpgrade linux-image-azure-fipsUpgrade linux-image-oem-24.04dUpgrade linux-image-5.4.0-1139-raspiUpgrade linux-image-azure-5.15Upgrade linux-image-oem-24.04cUpgrade linux-image-bluefieldUpgrade linux-image-xilinx-6.8Upgrade linux-image-raspi-5.4Upgrade linux-image-raspi2Upgrade linux-image-intel-iot-realtime-5.15Upgrade linux-image-xilinxUpgrade linux-image-azure-fips-6.8Upgrade linux-image-azure-cvmUpgrade linux-image-oem-24.04aUpgrade linux-image-raspi-hwe-18.04Upgrade linux-image-oem-6.17 | Apr 3, 2026 | Apr 1, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Apr 1, 2026 |
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