High 8.2Published Jul 25, 2026

CVE-2026-64435audit: Fix data races of skb_queue_len() readers on audit_queue

Updated under an hour ago (2026-10-19 07:50 UTC)

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In the Linux kernel, the following vulnerability has been resolved: audit: Fix data races of skb_queue_len() readers on audit_queue Multiple readers access audit_queue.qlen via skb_queue_len() without holding the queue lock or using READ_ONCE(), while kauditd writes to this field via the skb_dequeue() → __skb_unlink() path with WRITE_ONCE() protected by a spinlock. This constitutes data races. All affected skb_queue_len(&audit_queue) call sites: - kauditd_thread() wait_event_freezable() condition - audit_receive_msg() AUDIT_GET handler (s.backlog assignment) - audit_receive() backlog check - audit_log_start() backlog check and pr_warn() KCSAN reports the following conflicting access pattern (one example): ================================================================== BUG: KCSAN: data-race in audit_log_start / skb_dequeue write (marked) to 0xffffffff8512ee20 of 4 bytes by task 661 on cpu 57: skb_dequeue+0x70/0xf0 kauditd_send_queue+0x71/0x220 kauditd_thread+0x1cb/0x430 kthread+0x1c2/0x210 ret_from_fork+0x162/0x1a0 ret_from_fork_asm+0x1a/0x30 read to 0xffffffff8512ee20 of 4 bytes by task 36586 on cpu 1: audit_log_start+0x2a0/0x6b0 audit_core_dumps+0x64/0xa0 do_coredump+0x14b/0x1260 get_signal+0xeb2/0xf70 arch_do_signal_or_restart+0x41/0x170 exit_to_user_mode_loop+0xa2/0x1c0 do_syscall_64+0x1a3/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0xe0 value changed: 0x00000001 -> 0x00000000 ================================================================== Resolve the race by switching to lockless helper skb_queue_len_lockless(), which internally uses READ_ONCE() and properly pairs with the WRITE_ONCE() write accesses already present on the writer side. [PM: line length tweak]

CVSS: 8.2 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Oct 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	3197542482df22c2a131d4a813280bd7c54cedf5 builds before 69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0; from 3197542482df22c2a131d4a813280bd7c54cedf5 before b35597bdae1a5d8395da4b9baa993b9b71f74d68; from 3197542482df22c2a131d4a813280bd7c54cedf5 before e575dabb805252e3113fdc3f56f6ecacfde422d0; 3197542482df22c2a131d4a813280bd7c54cedf5 builds before 7ff42312ccde549f8c698723822c7db35107a39b; from 3197542482df22c2a131d4a813280bd7c54cedf5 before a3d85dec60bb0622360fc176b2a51abdbe2ff0ad; from 3197542482df22c2a131d4a813280bd7c54cedf5 before fe997a84a385f840b593ead92e575503a5046cee; from 3197542482df22c2a131d4a813280bd7c54cedf5 before c5186201fa7030289cc4fe23fae87a3fcb566856; from 3197542482df22c2a131d4a813280bd7c54cedf5 before c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7	CNA record
linux linux_kernel linux:linux_kernel	from 4.10 before 5.10.261; from 5.11 before 5.15.212; from 5.16 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.4; 7.2; and 1 more ranges	NVD

References

https://git.kernel.org/stable/c/69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0patch
https://git.kernel.org/stable/c/b35597bdae1a5d8395da4b9baa993b9b71f74d68patch
https://git.kernel.org/stable/c/e575dabb805252e3113fdc3f56f6ecacfde422d0patch
https://git.kernel.org/stable/c/7ff42312ccde549f8c698723822c7db35107a39bpatch
https://git.kernel.org/stable/c/a3d85dec60bb0622360fc176b2a51abdbe2ff0adpatch
https://git.kernel.org/stable/c/fe997a84a385f840b593ead92e575503a5046ceepatch
https://git.kernel.org/stable/c/c5186201fa7030289cc4fe23fae87a3fcb566856patch
https://git.kernel.org/stable/c/c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.