{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64435", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.787Z", "datePublished": "2026-07-25T08:51:09.688Z", "dateUpdated": "2026-08-17T04:55:36.444Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:55:36.444Z" }, "descriptions": [ { "lang": "en", "value": "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]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - Unauthenticated packets matching a pre-existing nftables audit-level logging or xtables AUDIT rule reach audit_log_start() through the network receive and netfilter paths.\nAC:L - Parallel matching traffic invokes the vulnerable readers while feeding and waking kauditd, allowing the attacker to repeatedly drive both sides of the race.\nPR:N - The audit rule must already be configured, but the remote attacker needs no credentials or capabilities to send matching packets.\nUI:N - No victim action is required after the affected network-audit configuration is active.\nS:U - The race and its effects remain within the host kernel and its audit security authority.\nC:N - The raced value is only the 32-bit queue length; no pointer, packet contents, or adjacent memory is disclosed.\nI:L - An incorrect backlog decision can delay or discard audit records, causing limited corruption of the security audit trail without an arbitrary-write primitive.\nA:H - In hardened systems using AUDIT_FAIL_PANIC, a raced queue length interpreted as exceeding the limit from the GFP_ATOMIC packet-audit path calls audit_log_lost() and can panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/audit.c" ], "versions": [ { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "b35597bdae1a5d8395da4b9baa993b9b71f74d68", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "e575dabb805252e3113fdc3f56f6ecacfde422d0", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "7ff42312ccde549f8c698723822c7db35107a39b", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "a3d85dec60bb0622360fc176b2a51abdbe2ff0ad", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "fe997a84a385f840b593ead92e575503a5046cee", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "c5186201fa7030289cc4fe23fae87a3fcb566856", "status": "affected", "versionType": "git" }, { "version": "3197542482df22c2a131d4a813280bd7c54cedf5", "lessThan": "c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/audit.c" ], "versions": [ { "version": "4.10", "status": "affected" }, { "version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0" }, { "url": "https://git.kernel.org/stable/c/b35597bdae1a5d8395da4b9baa993b9b71f74d68" }, { "url": "https://git.kernel.org/stable/c/e575dabb805252e3113fdc3f56f6ecacfde422d0" }, { "url": "https://git.kernel.org/stable/c/7ff42312ccde549f8c698723822c7db35107a39b" }, { "url": "https://git.kernel.org/stable/c/a3d85dec60bb0622360fc176b2a51abdbe2ff0ad" }, { "url": "https://git.kernel.org/stable/c/fe997a84a385f840b593ead92e575503a5046cee" }, { "url": "https://git.kernel.org/stable/c/c5186201fa7030289cc4fe23fae87a3fcb566856" }, { "url": "https://git.kernel.org/stable/c/c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7" } ], "title": "audit: Fix data races of skb_queue_len() readers on audit_queue", "x_generator": { "engine": "bippy-1.2.0" } } } }