A flaw in the Linux kernel’s fsnotify subsystem causes an inode reference leak when the __fsnotify_recalc_mask function returns an inode that is not released. The missing release leads to a pointer being dropped while the reference count remains incremented, resulting in a hung task that can block for extended periods. The consequence is a denial of service through a kernel memory resource exhaustion scenario, which can stall processes such as umount and potentially lock the system. The weakness aligns with the use-after-free resource release flaw as the inode pointer remains dangling.

Vendors: Linux; Product: Linux kernel. Versions: Any kernel build before the fix was applied; the exact affected releases are not enumerated in the data but the patch commits are referenced.

The CVSS score is not supplied and EPSS is not available, so the exact quantitative risk remains unknown. The vulnerability is not listed in the CISA KEV catalog, indicating no known exploitation. The likely attack vector involves manipulating fsnotify activity—such as adding and removing marks—through applications that use inotify or other monitoring facilities. This activity could be performed locally by a user with sufficient privileges or remotely if a privileged service exposes such interfaces. Because the issue can cause a hung task rather than a classic code‑execution vector, mitigation focuses on patching rather than containment.