A livelock occurs when the kernel’s quota handling routine, quotactl_block(), repeatedly retries waiting for a frozen filesystem to thaw. Because the kernel is running with preemption disabled, this retry loop never yields the CPU, preventing the RCU quiescent state needed for the freezer thread to proceed. The result is a freeze of the freezer process and sustained 100 % CPU usage by the quota process, effectively locking the system until the kernel is rebooted. This vulnerability can be triggered by concurrent usage of xfs_freeze and quota toggling on the same CPU core and represents a classic denial‑of‑service condition for filesystem administration.

The flaw affects all Linux kernel releases that include the upstream quotactl and freeze_super code paths prior to the patch that inserts a cond_resched() call. No specific version range is listed, so any kernel version affected by the linked commit is considered vulnerable.

Official CVSS or EPSS metrics are not provided, and the vulnerability is not catalogued in the CISA KEV list, indicating no known public exploitation. However, the livelock can be reliably reproduced on multi‑core systems and causes a full system hang, making it a high‑risk local denial‑of‑service. The lack of scheduling points makes the attack kernel‑level and requires the ability to invoke quota toggling while a filesystem is frozen on a shared CPU core.