{"id":"CVE-2026-64435","revision":"81b8560cf5134a1d81ae0dd297f06d75","records":[{"revision":"81b8560cf5134a1d81ae0dd297f06d75","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64435","aliases":[],"title":"audit: Fix data races of skb_queue_len() readers on audit_queue","description":"In the Linux kernel, the following vulnerability has been resolved:\n\naudit: Fix data races of skb_queue_len() readers on audit_queue\n\nMultiple readers access audit_queue.qlen via skb_queue_len() without\nholding the queue lock or using READ_ONCE(), while kauditd writes to\nthis field via the skb_dequeue() → __skb_unlink() path with WRITE_ONCE()\nprotected by a spinlock. This constitutes data races.\n\nAll affected skb_queue_len(&audit_queue) call sites:\n  - kauditd_thread() wait_event_freezable() condition\n  - audit_receive_msg() AUDIT_GET handler (s.backlog assignment)\n  - audit_receive() backlog check\n  - audit_log_start() backlog check and pr_warn()\n\nKCSAN reports the following conflicting access pattern (one example):\n==================================================================\nBUG: KCSAN: data-race in audit_log_start / skb_dequeue\n\nwrite (marked) to 0xffffffff8512ee20 of 4 bytes by task 661 on cpu 57:\n skb_dequeue+0x70/0xf0\n kauditd_send_queue+0x71/0x220\n kauditd_thread+0x1cb/0x430\n kthread+0x1c2/0x210\n ret_from_fork+0x162/0x1a0\n ret_from_fork_asm+0x1a/0x30\n\nread to 0xffffffff8512ee20 of 4 bytes by task 36586 on cpu 1:\n audit_log_start+0x2a0/0x6b0\n audit_core_dumps+0x64/0xa0\n do_coredump+0x14b/0x1260\n get_signal+0xeb2/0xf70\n arch_do_signal_or_restart+0x41/0x170\n exit_to_user_mode_loop+0xa2/0x1c0\n do_syscall_64+0x1a3/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0xe0\n\nvalue changed: 0x00000001 -> 0x00000000\n==================================================================\n\nResolve the race by switching to lockless helper skb_queue_len_lockless(),\nwhich internally uses READ_ONCE() and properly pairs with the WRITE_ONCE()\nwrite accesses already present on the writer side.\n\n[PM: line length tweak]","state":0,"publishedAt":"2026-07-25T08:51:09.688+00:00","modifiedAt":"2026-10-19T20:38:28.743+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/audit.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"b35597bdae1a5d8395da4b9baa993b9b71f74d68\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"e575dabb805252e3113fdc3f56f6ecacfde422d0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"7ff42312ccde549f8c698723822c7db35107a39b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"a3d85dec60bb0622360fc176b2a51abdbe2ff0ad\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"fe997a84a385f840b593ead92e575503a5046cee\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"c5186201fa7030289cc4fe23fae87a3fcb566856\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3197542482df22c2a131d4a813280bd7c54cedf5\",\n                            \"lessThan\": \"c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/audit.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.10\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.96\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.39\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.4\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","score":8.2,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0","https://git.kernel.org/stable/c/b35597bdae1a5d8395da4b9baa993b9b71f74d68","https://git.kernel.org/stable/c/e575dabb805252e3113fdc3f56f6ecacfde422d0","https://git.kernel.org/stable/c/7ff42312ccde549f8c698723822c7db35107a39b","https://git.kernel.org/stable/c/a3d85dec60bb0622360fc176b2a51abdbe2ff0ad","https://git.kernel.org/stable/c/fe997a84a385f840b593ead92e575503a5046cee","https://git.kernel.org/stable/c/c5186201fa7030289cc4fe23fae87a3fcb566856","https://git.kernel.org/stable/c/c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64435","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64435","identifiers":["CVE-2026-64435"]},"retained":false,"historicalAffected":[]}],"coverage":[]}