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CVE-2026-64435

audit: Fix data races of skb_queue_len() readers on audit_queue

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, and 2 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

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]

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • Linux Linux

    From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in 69f98fff30bdaa72b0cb0e7e078ab6456a0a59b0; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in b35597bdae1a5d8395da4b9baa993b9b71f74d68; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in e575dabb805252e3113fdc3f56f6ecacfde422d0; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in 7ff42312ccde549f8c698723822c7db35107a39b; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in a3d85dec60bb0622360fc176b2a51abdbe2ff0ad; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in fe997a84a385f840b593ead92e575503a5046cee; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in c5186201fa7030289cc4fe23fae87a3fcb566856; From 3197542482df22c2a131d4a813280bd7c54cedf5 · fixed in c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7

  • Linux Linux

    4.10

  • KernelLinux

    From 4.10.0 · fixed in 5.10.261; From 5.11.0 · fixed in 5.15.212; From 5.16.0 · fixed in 6.1.178; From 6.2.0 · fixed in 6.6.145; From 6.7.0 · fixed in 6.12.96; From 6.13.0 · fixed in 6.18.39; From 6.19.0 · fixed in 7.1.4

References 8

git.kernel.org