CVE-2026-45895

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A livelock issue exists between quotactl and freeze super in kernels with preemption disabled. When a filesystem is frozen, the quotactl block() function enters a retry loop using the sb start write() and sb end write() pair to wait for the filesystem to thaw. Simultaneously, freeze super() sets SB FREEZE WRITE and calls sb wait write(), which triggers percpu down write() and subsequently synchronize rcu(). Because the kernel is non-preemptible and the quotactl block() loop lacks scheduling points, the CPU never yields, preventing it from reaching an RCU quiescent state. This causes synchronize rcu() to wait indefinitely, while quotactl block() continues to spin, resulting in a hang of the freezer process and 100% CPU usage by the quota process.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.