In the Linux kernel, the following vulnerability has been resolved: dcache: don't put a mountpoint on a dentry that's being removed rmdir(),… (CVE-2026-98984)

The Linux kernel vulnerability (CVE-2026-98984) concerns the dcache subsystem where mountpoints can be incorrectly assigned to dentries that are in the process of being removed. Specifically, rmdir(), unlink(), and rename() call dont_mount() and detach_mounts() with inode locks to prevent mounts on victims. However, attach_recursive_mnt() creates a second mountpoint for the source mount root without locking the inode, allowing a bind mount of a directory being removed to be moved beneath an existing mount. This results in a mountpoint attached to a removed directory that cannot be detached, due to the victim dentry still being hashed between detach_mounts() and d_delete(). The fix involves checking cant_mount() in d_set_mounted() to prevent this scenario.

The vulnerability allows a mountpoint to be attached to a directory that is in the process of being removed, causing the mount to persist indefinitely and never be detached. This could lead to resource management issues or inconsistencies in the filesystem mount state. No direct exploitation details or broader impact scenarios are provided in the data.

The vulnerability has been resolved in the Linux kernel. Users should apply the official kernel updates that include the fix for CVE-2026-98984. Since no patch links or vendor advisories are provided here, users should consult their Linux distribution's security advisories for the relevant kernel update. No additional mitigation steps are indicated.