Description
In the Linux kernel, the following vulnerability has been resolved:
__legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock
... or we risk stealing final mntput from sync umount - raising mnt_count after umount(2) has verified that victim is not busy, but before it has set MNT_SYNC_UMOUNT; in that case __legitimize_mnt() doesn't see that it's safe to quietly undo mnt_count increment and leaves dropping the reference to caller, where it'll be a full-blown mntput().
Check under mount_lock is needed; leaving the current one done before taking that makes no sense - it's nowhere near common enough to bother with.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
No affected versions have been published.
Timeline
- Published
- Jun 18, 2025
- Last modified
- Oct 15, 2026
- NVD status
- Modified