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High · 7.8 CVE-2026-23407 EUVD-2026-17835GHSA-6cp6-7hgg-4x9m

apparmor: fix missing bounds check on DEFAULT table in verify_dfa()

Published Apr 1, 2026 · Updated Aug 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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.

Affected products

VendorProductAffectedFixed
Linux Linux 4.17 5.10.253

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.19.6-2 —
Debian 13 linux 6.12.74-2 —
Debian 12 linux 6.1.164-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1017.21 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1087.89 —
Ubuntu 25.10 linux 6.17.0-19.19 —
Ubuntu 25.10 linux-aws +2 6.17.0-1009.9 —
Ubuntu 25.10 linux-azure +1 6.17.0-1010.10 —
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-realtime 6.17.0-1008.9 —
Ubuntu 25.10 linux-riscv 6.17.0-19.19.1 —
Ubuntu 24.04 LTS linux 6.8.0-106.106 —
Ubuntu 24.04 LTS linux-aws 6.8.0-1050.53 —
Ubuntu 24.04 LTS linux-aws-6.17 6.17.0-1009.9~24.04.2 —
Ubuntu 24.04 LTS linux-azure 6.8.0-1051.57 —
Ubuntu 24.04 LTS linux-azure-6.17 6.17.0-1010.10~24.04.1 —
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1058.65 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1052.55 —
Ubuntu 24.04 LTS linux-gcp-6.17 6.17.0-1009.9~24.04.3 —
Ubuntu 24.04 LTS linux-gke 6.8.0-1048.53 —
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1035.38 —
Ubuntu 24.04 LTS linux-hwe-6.17 6.17.0-19.19~24.04.2 —
Ubuntu 24.04 LTS linux-ibm 6.8.0-1049.49 —
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-106.106.1 —
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1049.52 —
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1014.14 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1049.52.1 —
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1020.20 —
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1017.17 USN-8152-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1047.48 —
Ubuntu 24.04 LTS linux-oracle-6.17 6.17.0-1009.9~24.04.1 —
Ubuntu 24.04 LTS linux-raspi 6.8.0-1050.54 —
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-riscv-6.17 6.17.0-19.19.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1028.29 USN-8261-1
Ubuntu 22.04 LTS linux +1 5.15.0-173.183 —
Ubuntu 22.04 LTS linux-aws 5.15.0-1103.110 —
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1050.53~22.04.1 —
Ubuntu 22.04 LTS linux-azure 5.15.0-1109.118 USN-8163-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1051.57~22.04.1 —
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1109.118.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1103.112 —
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1052.55~22.04.1 —
Ubuntu 22.04 LTS linux-gke 5.15.0-1099.105 —
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1086.94 —
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-106.106~22.04.1 —
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1097.100 —
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1049.49~22.04.1 —
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1098.104 —
Ubuntu 22.04 LTS linux-kvm 5.15.0-1095.100 —
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-106.106.1~22.04.1 —
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1098.99 —
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1049.52~22.04.1 —
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1055.55 —
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1044.44 —
Ubuntu 22.04 LTS linux-oracle 5.15.0-1100.106 —
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1047.48~22.04.1 —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1067.71 —
Show 12 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2040.41 —
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1045.46 —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1008.9~24.04.1 —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1096.98 USN-8164-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1102.111 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1045.46~22.04.1 —
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1050.53+fips1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1052.58+fips1 USN-8165-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-106.106+fips1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1052.55+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1103.110+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1109.118+fips1 USN-8163-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-173.183+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1103.112+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-aws-fips 5.4.0-1156.166+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-azure-fips 5.4.0-1160.166+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips 5.4.0-1130.140 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-gcp-fips 5.4.0-1159.168+fips1 —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux 5.4.0-227.247 —
Ubuntu Pro 20.04 LTS linux-aws 5.4.0-1156.166 —
Ubuntu Pro 20.04 LTS linux-aws-5.15 5.15.0-1103.110~20.04.1 —
Ubuntu Pro 20.04 LTS linux-azure 5.4.0-1160.166 —
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1110.119~20.04.1 USN-8243-1
Ubuntu Pro 20.04 LTS linux-bluefield 5.4.0-1116.123 USN-8224-1
Ubuntu Pro 20.04 LTS linux-gcp 5.4.0-1159.168 —
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1103.112~20.04.1 —
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-173.183~20.04.1 —
Ubuntu Pro 20.04 LTS linux-ibm 5.4.0-1102.107 —
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1097.100~20.04.1 —
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1098.104~20.04.1 —
Ubuntu Pro 20.04 LTS linux-iot 5.4.0-1060.63 —
Ubuntu Pro 20.04 LTS linux-kvm 5.4.0-1143.152 —
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1055.55~20.04.1 —
Ubuntu Pro 20.04 LTS linux-oracle 5.4.0-1154.164 —
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1100.106~20.04.1 —
Ubuntu Pro 20.04 LTS linux-raspi 5.4.0-1139.152 USN-8098-10
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1098.102~20.04.1 —
Ubuntu Pro 20.04 LTS linux-xilinx-zynqmp 5.4.0-1074.78 —
Ubuntu Pro 18.04 LTS linux-aws-5.4 5.4.0-1156.166~18.04.1 —
Ubuntu Pro 18.04 LTS linux-azure-5.4 5.4.0-1161.167~18.04.1 USN-8201-1
Ubuntu Pro 18.04 LTS linux-gcp-5.4 5.4.0-1159.168~18.04.1 —
Ubuntu Pro 18.04 LTS linux-hwe-5.4 5.4.0-227.247~18.04.1 —
Ubuntu Pro 18.04 LTS linux-ibm-5.4 5.4.0-1102.107~18.04.1 —
Ubuntu Pro 18.04 LTS linux-oracle-5.4 5.4.0-1154.164~18.04.1 —
Ubuntu Pro 18.04 LTS linux-raspi-5.4 5.4.0-1139.152~18.04.1 USN-8098-10
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +7 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.55.1.150700.17.33.1 SUSE-SU-2026:2238-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.112.1.150600.12.52.1 SUSE-SU-2026:2195-1
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.112.1.150600.12.52.1 SUSE-SU-2026:2195-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLE Micro 6.2 kernel-syms +1 6.12.0-160000.33.1 SUSE-SU-2026:21834-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.55.1 SUSE-SU-2026:2238-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_15 1-150700.15.3.1 SUSE-SU-2026:2238-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.112.1 SUSE-SU-2026:2195-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_26 1-150600.13.3.1 SUSE-SU-2026:2195-1

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.130.1-1 —

Advisories 14

References