CVE-2023-53731: netlink: fix potential deadlock in netlink_set_err()

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-22 · updated 2026-10-28

Description

In the Linux kernel, the following vulnerability has been resolved: netlink: fix potential deadlock in netlink_set_err() syzbot reported a possible deadlock in netlink_set_err() [1] A similar issue was fixed in commit 1d482e666b8e ("netlink: disable IRQs for netlink_lock_table()") in netlink_lock_table() This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump() which were not covered by cited commit. [1] WARNING: possible irq lock inversion dependency detected 6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted syz-executor.2/23011 just changed the state of lock: ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netlink_set_err+0x2e/0x3a0 net/netlink/af_netlink.c:1612 but this lock was taken by another, SOFTIRQ-safe lock in the past: (&local->queue_stop_reason_lock){..-.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(nl_table_lock); local_irq_disable(); lock(&local->queue_stop_reason_lock); lock(nl_table_lock); <Interrupt> lock(&local->queue_stop_reason_lock); *** DEADLOCK ***

Affected products

Linux kernel: from 4.14.237 before 4.14.322; from 4.19.195 before 4.19.291; from 5.4.126 before 5.4.251; from 5.10.44 before 5.10.188; from 4.4.273 before 4.5; from 4.9.273 before 4.10 — fixed in 4.10, 4.14.322, 4.19.291, 4.5, 5.10.188, 5.13

How to fix

Upgrade to a fixed version: Linux kernel 4.10, 4.14.322, 4.19.291, 4.5. Check the vendor advisory for mitigations.

References

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