CVE-2025-38058: Debian Linux

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: before 5.4.294 (fixed in 5.4.294); from 5.5, before 5.10.238 (fixed in 5.10.238); from 5.11, before 5.15.185 (fixed in 5.15.185); from 5.16, before 6.1.141 (fixed in 6.1.141); from 6.2, before 6.6.93 (fixed in 6.6.93); from 6.7, before 6.12.31 (fixed in 6.12.31); …

Published 2025-06-18. Last modified 2026-07-30.