CVE Vulnerabilities

CVE-2026-64435

Published: Jul 25, 2026 | Modified: Jul 27, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM
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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]

Affected Software

NameVendorStart VersionEnd Version
Linux-allwinner-5.19Ubuntujammy*
Linux-allwinner-5.19Ubuntuupstream*
Linux-aws-5.0Ubuntuesm-infra/bionic*
Linux-aws-5.0Ubuntuupstream*
Linux-aws-5.11Ubuntuesm-infra/focal*
Linux-aws-5.11Ubuntuupstream*
Linux-aws-5.13Ubuntuesm-infra/focal*
Linux-aws-5.13Ubuntuupstream*
Linux-aws-5.19Ubuntujammy*
Linux-aws-5.19Ubuntuupstream*
Linux-aws-5.3Ubuntuesm-infra/bionic*
Linux-aws-5.3Ubuntuupstream*
Linux-aws-5.8Ubuntuesm-infra/focal*
Linux-aws-5.8Ubuntuupstream*
Linux-aws-6.2Ubuntujammy*
Linux-aws-6.2Ubuntuupstream*
Linux-aws-6.5Ubuntujammy*
Linux-aws-6.5Ubuntuupstream*
Linux-azureUbuntuesm-infra/bionic*
Linux-azure-5.11Ubuntuesm-infra/focal*
Linux-azure-5.11Ubuntuupstream*
Linux-azure-5.13Ubuntuesm-infra/focal*
Linux-azure-5.13Ubuntuupstream*
Linux-azure-5.19Ubuntujammy*
Linux-azure-5.19Ubuntuupstream*
Linux-azure-5.3Ubuntuesm-infra/bionic*
Linux-azure-5.3Ubuntuupstream*
Linux-azure-5.8Ubuntuesm-infra/focal*
Linux-azure-5.8Ubuntuupstream*
Linux-azure-6.11Ubuntunoble*
Linux-azure-6.11Ubuntuupstream*
Linux-azure-6.2Ubuntujammy*
Linux-azure-6.2Ubuntuupstream*
Linux-azure-6.5Ubuntujammy*
Linux-azure-6.5Ubuntuupstream*
Linux-azure-edgeUbuntuesm-infra/bionic*
Linux-azure-edgeUbuntuupstream*
Linux-azure-fdeUbuntuesm-infra/focal*
Linux-azure-fde-5.19Ubuntujammy*
Linux-azure-fde-5.19Ubuntuupstream*
Linux-azure-fde-6.2Ubuntujammy*
Linux-azure-fde-6.2Ubuntuupstream*
Linux-gcpUbuntuesm-infra/bionic*
Linux-gcp-5.11Ubuntuesm-infra/focal*
Linux-gcp-5.11Ubuntuupstream*
Linux-gcp-5.13Ubuntuesm-infra/focal*
Linux-gcp-5.13Ubuntuupstream*
Linux-gcp-5.19Ubuntujammy*
Linux-gcp-5.19Ubuntuupstream*
Linux-gcp-5.3Ubuntuesm-infra/bionic*
Linux-gcp-5.3Ubuntuupstream*
Linux-gcp-5.8Ubuntuesm-infra/focal*
Linux-gcp-5.8Ubuntuupstream*
Linux-gcp-6.11Ubuntunoble*
Linux-gcp-6.11Ubuntuupstream*
Linux-gcp-6.2Ubuntujammy*
Linux-gcp-6.2Ubuntuupstream*
Linux-gcp-6.5Ubuntujammy*
Linux-gcp-6.5Ubuntuupstream*
Linux-gkeUbuntuesm-infra/focal*
Linux-gke-4.15Ubuntuesm-infra/bionic*
Linux-gke-4.15Ubuntuupstream*
Linux-gke-5.15Ubuntuesm-infra/focal*
Linux-gke-5.15Ubuntuupstream*
Linux-gke-5.4Ubuntuesm-infra/bionic*
Linux-gke-5.4Ubuntuupstream*
Linux-gkeopUbuntuesm-infra/focal*
Linux-gkeop-5.15Ubuntuesm-infra/focal*
Linux-gkeop-5.4Ubuntuesm-infra/bionic*
Linux-gkeop-5.4Ubuntuupstream*
Linux-hweUbuntuesm-infra/bionic*
Linux-hwe-5.11Ubuntuesm-infra/focal*
Linux-hwe-5.11Ubuntuupstream*
Linux-hwe-5.13Ubuntuesm-infra/focal*
Linux-hwe-5.13Ubuntuupstream*
Linux-hwe-5.19Ubuntujammy*
Linux-hwe-5.19Ubuntuupstream*
Linux-hwe-5.8Ubuntuesm-infra/focal*
Linux-hwe-5.8Ubuntuupstream*
Linux-hwe-6.11Ubuntunoble*
Linux-hwe-6.11Ubuntuupstream*
Linux-hwe-6.2Ubuntujammy*
Linux-hwe-6.2Ubuntuupstream*
Linux-hwe-6.5Ubuntujammy*
Linux-hwe-6.5Ubuntuupstream*
Linux-hwe-edgeUbuntuesm-infra-legacy/xenial*
Linux-hwe-edgeUbuntuesm-infra/bionic*
Linux-hwe-edgeUbuntuupstream*
Linux-intel-5.13Ubuntuesm-infra/focal*
Linux-intel-5.13Ubuntuupstream*
Linux-intel-iot-realtimeUbuntujammy*
Linux-lowlatency-hwe-5.19Ubuntujammy*
Linux-lowlatency-hwe-5.19Ubuntuupstream*
Linux-lowlatency-hwe-6.11Ubuntunoble*
Linux-lowlatency-hwe-6.11Ubuntuupstream*
Linux-lowlatency-hwe-6.2Ubuntujammy*
Linux-lowlatency-hwe-6.2Ubuntuupstream*
Linux-lowlatency-hwe-6.5Ubuntujammy*
Linux-lowlatency-hwe-6.5Ubuntuupstream*
Linux-nvidia-6.11Ubuntunoble*
Linux-nvidia-6.11Ubuntuupstream*
Linux-nvidia-6.2Ubuntujammy*
Linux-nvidia-6.2Ubuntuupstream*
Linux-nvidia-6.5Ubuntujammy*
Linux-nvidia-6.5Ubuntuupstream*
Linux-oemUbuntuesm-infra/bionic*
Linux-oemUbuntuupstream*
Linux-oem-5.10Ubuntuesm-infra/focal*
Linux-oem-5.10Ubuntuupstream*
Linux-oem-5.13Ubuntuesm-infra/focal*
Linux-oem-5.13Ubuntuupstream*
Linux-oem-5.14Ubuntuesm-infra/focal*
Linux-oem-5.14Ubuntuupstream*
Linux-oem-5.17Ubuntujammy*
Linux-oem-5.17Ubuntuupstream*
Linux-oem-5.6Ubuntuesm-infra/focal*
Linux-oem-5.6Ubuntuupstream*
Linux-oem-6.0Ubuntujammy*
Linux-oem-6.0Ubuntuupstream*
Linux-oem-6.1Ubuntujammy*
Linux-oem-6.1Ubuntuupstream*
Linux-oem-6.11Ubuntunoble*
Linux-oem-6.11Ubuntuupstream*
Linux-oem-6.5Ubuntujammy*
Linux-oem-6.5Ubuntuupstream*
Linux-oem-6.8Ubuntunoble*
Linux-oem-6.8Ubuntuupstream*
Linux-oracle-5.0Ubuntuesm-infra/bionic*
Linux-oracle-5.0Ubuntuupstream*
Linux-oracle-5.11Ubuntuesm-infra/focal*
Linux-oracle-5.11Ubuntuupstream*
Linux-oracle-5.13Ubuntuesm-infra/focal*
Linux-oracle-5.13Ubuntuupstream*
Linux-oracle-5.3Ubuntuesm-infra/bionic*
Linux-oracle-5.3Ubuntuupstream*
Linux-oracle-5.8Ubuntuesm-infra/focal*
Linux-oracle-5.8Ubuntuupstream*
Linux-oracle-6.5Ubuntujammy*
Linux-oracle-6.5Ubuntuupstream*
Linux-raspi-realtimeUbuntunoble*
Linux-raspi2Ubuntuesm-infra/focal*
Linux-raspi2Ubuntuupstream*
Linux-realtimeUbuntujammy*
Linux-realtimeUbuntunoble*
Linux-riscvUbuntuesm-infra/focal*
Linux-riscvUbuntujammy*
Linux-riscvUbuntunoble*
Linux-riscv-5.11Ubuntuesm-infra/focal*
Linux-riscv-5.11Ubuntuupstream*
Linux-riscv-5.19Ubuntujammy*
Linux-riscv-5.19Ubuntuupstream*
Linux-riscv-5.8Ubuntuesm-infra/focal*
Linux-riscv-5.8Ubuntuupstream*
Linux-riscv-6.14Ubuntunoble*
Linux-riscv-6.14Ubuntuupstream*
Linux-riscv-6.5Ubuntujammy*
Linux-riscv-6.5Ubuntuupstream*
Linux-starfive-5.19Ubuntujammy*
Linux-starfive-5.19Ubuntuupstream*
Linux-starfive-6.2Ubuntujammy*
Linux-starfive-6.2Ubuntuupstream*
Linux-starfive-6.5Ubuntujammy*
Linux-starfive-6.5Ubuntuupstream*

References