Deadlock Handling Vulnerability in Linux Kernel's rqspinlock by Linux Foundation

CVE-2026-74686

What is CVE-2026-74686?

A vulnerability in the Linux kernel's rqspinlock can lead to indefinite stalls during deadlock scenarios. When a deadlock is detected, the system may suppress destruction of the waiter queue, preventing it from effectively signaling next waiters due to a lack of proper tail reset processing. This leads to potential indefinite waiting periods for threads in specific deadlock conditions, particularly with ABBA deadlocks, if no subsequent waiters are queued correctly. A patch has been introduced to rectify this logic, improving the overall stability and responsiveness of the kernel in deadlock situations.

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