In the Linux kernel the rseq subsystem grants a time‑slice extension incorrectly while interrupts are still enabled, causing a call to hrtimer_rearm_deferred_tif() that should run with interrupts disabled. The function acquires a raw_spin_lock while interrupts remain active, leading to a livelock that lockdep reports as an inconsistent lock state warning. This race condition is identified as CWE‑366. If this condition is triggered, the system can enter a hard lockup during a context switch, effectively crashing the system and causing a denial of service.

The vulnerability exists in any Linux kernel build that does not contain the rseq patch. All distributions that ship the upstream kernel unchanged are potentially affected. No specific affected kernel version ranges are enumerated in the advisory, so any system running an older kernel lacking the fix remains vulnerable.

The EPSS score is not available and the bug is not listed in the CISA KEV catalog. The CVSS score of 5.5 indicates moderate severity. Based on the description it is inferred that the vulnerability requires the attacker to run code in kernel mode, such as through a local privilege escalation or a malicious kernel module. No publicly disclosed exploits exist, and no remote attack path is known. Consequently, the risk is limited to environments where an attacker can execute code in the kernel; the likelihood of exploitation remains primarily theoretical.