The Linux kernel contains a flaw in the XFS filesystem online check that can cause an infinite loop during inode unlink processing. The bug arises because previously seen inodes are not tracked, leading the linked list traversal to repeat indefinitely. If this loop occurs, the filesystem check will hang, potentially exhausting CPU or memory resources and interrupting normal system operation. The impact is a loss of availability for the affected filesystem, as the online fsck cannot complete and may require a reboot or manual intervention.

All Linux distributions that include the Linux kernel with an XFS filesystem support, prior to the inclusion of the patch that records visited inodes during online fsck. The exact kernel versions are not enumerated in the advisory, so any kernel offering XFS online check before the commit fixing this issue is considered affected.

The vulnerability lacks an EPSS score and is not listed in the CISA KEV catalog, indicating it has not yet been widely exploited in the wild. However, an attacker with local or privileged access could trigger a denial of service by initiating an online fsck on a filesystem that experiences this loop. Without the patch, the loop can persist indefinitely, causing prolonged downtime. The exact difficulty of exploitation depends on the ability to run an online fsck, which typically requires root privileges, making the risk higher for systems with misconfigured sudo or similar privileges.