In the Linux kernel, the sequence that grants a time‑slice extension in the rseq subsystem incorrectly calls rseq_grant_timeslice_extension() with interrupts enabled. The routine subsequently invokes hrtimer_rearm_deferred_tif(), which is designed to run with interrupts disabled and acquires a raw_spin_lock. Because interrupts were still enabled, the lock acquisition can dead‑lock, resulting in a livelock scenario that lockdep reports as an inconsistent lock state warning. If this condition is triggered, the kernel 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 vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that the vulnerability requires the ability to execute code in kernel mode (e.g., via 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 run code in the kernel; the likelihood of exploitation remains primarily theoretical.