{"id":"CVE-2026-23407","summary":"apparmor: fix missing bounds check on DEFAULT table in verify_dfa()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix missing bounds check on DEFAULT table in verify_dfa()\n\nThe verify_dfa() function only checks DEFAULT_TABLE bounds when the state\nis not differentially encoded.\n\nWhen the verification loop traverses the differential encoding chain,\nit reads k = DEFAULT_TABLE[j] and uses k as an array index without\nvalidation. A malformed DFA with DEFAULT_TABLE[j] \u003e= state_count,\ntherefore, causes both out-of-bounds reads and writes.\n\n[   57.179855] ==================================================================\n[   57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660\n[   57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993\n\n[   57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\n[   57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   57.181563] Call Trace:\n[   57.181572]  \u003cTASK\u003e\n[   57.181577]  dump_stack_lvl+0x5e/0x80\n[   57.181596]  print_report+0xc8/0x270\n[   57.181605]  ? verify_dfa+0x59a/0x660\n[   57.181608]  kasan_report+0x118/0x150\n[   57.181620]  ? verify_dfa+0x59a/0x660\n[   57.181623]  verify_dfa+0x59a/0x660\n[   57.181627]  aa_dfa_unpack+0x1610/0x1740\n[   57.181629]  ? __kmalloc_cache_noprof+0x1d0/0x470\n[   57.181640]  unpack_pdb+0x86d/0x46b0\n[   57.181647]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   57.181653]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   57.181656]  ? aa_unpack_nameX+0x1a8/0x300\n[   57.181659]  aa_unpack+0x20b0/0x4c30\n[   57.181662]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   57.181664]  ? stack_depot_save_flags+0x33/0x700\n[   57.181681]  ? kasan_save_track+0x4f/0x80\n[   57.181683]  ? kasan_save_track+0x3e/0x80\n[   57.181686]  ? __kasan_kmalloc+0x93/0xb0\n[   57.181688]  ? __kvmalloc_node_noprof+0x44a/0x780\n[   57.181693]  ? aa_simple_write_to_buffer+0x54/0x130\n[   57.181697]  ? policy_update+0x154/0x330\n[   57.181704]  aa_replace_profiles+0x15a/0x1dd0\n[   57.181707]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   57.181710]  ? __kvmalloc_node_noprof+0x44a/0x780\n[   57.181712]  ? aa_loaddata_alloc+0x77/0x140\n[   57.181715]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   57.181717]  ? _copy_from_user+0x2a/0x70\n[   57.181730]  policy_update+0x17a/0x330\n[   57.181733]  profile_replace+0x153/0x1a0\n[   57.181735]  ? rw_verify_area+0x93/0x2d0\n[   57.181740]  vfs_write+0x235/0xab0\n[   57.181745]  ksys_write+0xb0/0x170\n[   57.181748]  do_syscall_64+0x8e/0x660\n[   57.181762]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n[   57.181765] RIP: 0033:0x7f6192792eb2\n\nRemove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE\nentries unconditionally.","modified":"2026-04-03T11:03:47.320055Z","published":"2026-04-01T08:36:37.197Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23407.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/76b4d36c5122866452d34d8f79985e191f9c3831"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c7cf05e0606f554c467e3a4dc49e2e578a755b4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d352873bbefa7eb39995239d0b44ccdf8aaa79a4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23407.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23407"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"031dcc8f4e84fea37dc6f78fdc7288aa7f8386c3"},{"fixed":"7c7cf05e0606f554c467e3a4dc49e2e578a755b4"},{"fixed":"76b4d36c5122866452d34d8f79985e191f9c3831"},{"fixed":"5a68e46dfe0c8c8ffc6f425ebc4cae6238566ecc"},{"fixed":"f39e126e56c6ec1930fae51ad6bca3dae2a4c3ed"},{"fixed":"d352873bbefa7eb39995239d0b44ccdf8aaa79a4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23407.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.17.0"},{"fixed":"6.6.130"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.77"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.18"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23407.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}