CVE-2024-47660: Linux Kernel

Medium severity, CVSS 4.7. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: fsnotify: clear PARENT_WATCHED flags lazily In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users. Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children. When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.

Affected products

• Linux Linux Kernel: before 5.10.226 (fixed in 5.10.226); from 5.11, before 5.15.167 (fixed in 5.15.167); from 5.16, before 6.1.109 (fixed in 6.1.109); from 6.2, before 6.6.50 (fixed in 6.6.50); from 6.7, before 6.10.9 (fixed in 6.10.9)

Published 2024-10-09. Last modified 2026-06-17.