p PatchFirst

CVE-2026-98995

CVE-2026-98995 · namespace: reset the old parent's ->overmount in mnt_change_mountpoint()

This page contains facts from public vulnerability sources. Check the original advisory before updating.

In the Linux kernel, the following vulnerability has been resolved: namespace: reset the old parent's ->overmount in mnt_change_mountpoint() __umount_mnt() resets ->overmount of the parent when it unmounts the mount that overmounts it. mnt_change_mountpoint() doesn't. It moves the mount to its new parent and leaves the old one pointing at it. For a mount that is moved beneath in attach_recursive_mnt() that doesn't matter. The new mount has already reset ->overmount of the old parent by the time the old top mount is moved onto it. It matters for reparent() though. propagate_umount() moves a surviving overmount onto the first ancestor that isn't going to be unmounted. The mount it was taken from is unmounted immediately afterwards. If a file descriptor keeps that unmounted mount alive ->overmount points at the moved mount. That's a dangling pointer and UAF as the moved mount is unmounted and freed. do_lock_mount() follows ->overmount from the target path under mount_lock. With a file descriptor on such a mount as the target of a mount beneath topmost_overmount() walks into the freed mount and do_lock_mount() takes references on whatever it finds there. So reset ->overmount of the old parent in mnt_change_mountpoint() the same way __umount_mnt() does. A mount's ->overmount is then always a mount that is attached to it.

Fix available

Published
Updated

Stack: system

Affected products and versions

  • linux

    Versions
    • ≥ ffdc52fbbd5835a936ad683c943d6d103a2d4514, < 5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5: Affected (git)
    • ≥ ffdc52fbbd5835a936ad683c943d6d103a2d4514, < 08d575ee89393fd812dbdca7b5d7b4574cd5a564: Affected (git)
    • ≥ ffdc52fbbd5835a936ad683c943d6d103a2d4514, < 476ef286a7a5db8bda51325dc0c45887b4d99d9a: Affected (git)

    Update to 5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5

  • linux

    Versions
    • 6.17: Affected
    • ≥ 0, < 6.17: Not affected (semver)
    • ≥ 6.18.57, ≤ 6.18.*: Not affected (semver)
    • ≥ 7.2.11, ≤ 7.2.*: Not affected (semver)
    • ≥ 7.3: Not affected (original_commit_for_fix)

    No fix published

  • linux Debian:14

    Versions
    • 6.12.100-1
    • 6.12.101-1
    • 6.12.105-1
    • 6.12.107-1
    • 6.12.111-1
    • 6.12.113-1
    • 6.12.38-1
    • 6.12.41-1
    • 6.12.43-1
    • 6.12.43-1~bpo12+1
    • 6.12.48-1
    • 6.12.57-1
    • 6.12.57-1~bpo12+1
    • 6.12.63-1
    • 6.12.63-1~bpo12+1
    • 6.12.69-1
    • 6.12.69-1~bpo12+1
    • 6.12.73-1
    • 6.12.73-1~bpo12+1
    • 6.12.74-1
    • 6.12.74-2
    • 6.12.74-2~bpo12+1
    • 6.12.85-1
    • 6.12.85-1~bpo12+1
    • 6.12.86-1
    • 6.12.86-1~bpo12+1
    • 6.12.88-1
    • 6.12.88-1~bpo12+1
    • 6.12.90-1
    • 6.12.90-1~bpo12+1
    • 6.12.90-2
    • 6.12.90-2~bpo12+1
    • 6.12.94-1
    • 6.12.94-1~bpo12+1
    • 6.12.95-1
    • 6.12.95-1~bpo12+1
    • 6.12.96-1
    • 6.13.10-1~exp1
    • 6.13.11-1~exp1
    • 6.13.2-1~exp1
    • 6.13.3-1~exp1
    • 6.13.4-1~exp1
    • 6.13.5-1~exp1
    • 6.13.6-1~exp1
    • 6.13.7-1~exp1
    • 6.13.8-1~exp1
    • 6.13.9-1~exp1
    • 6.13~rc6-1~exp1
    • 6.13~rc7-1~exp1
    • 6.14.3-1~exp1
    • 6.14.5-1~exp1
    • 6.14.6-1~exp1
    • 6.15-1~exp1
    • 6.15.1-1~exp1
    • 6.15.2-1~exp1
    • 6.15.3-1~exp1
    • 6.15.4-1~exp1
    • 6.15.5-1~exp1
    • 6.15.6-1~exp1
    • 6.15~rc7-1~exp1
    • 6.16-1~exp1
    • 6.16.1-1~exp1
    • 6.16.10-1
    • 6.16.11-1
    • 6.16.12-1
    • 6.16.12-1~bpo13+1
    • 6.16.12-2
    • 6.16.3-1
    • 6.16.3-1~bpo13+1
    • 6.16.5-1
    • 6.16.6-1
    • 6.16.7-1
    • 6.16.8-1
    • 6.16.9-1
    • 6.16~rc7-1~exp1
    • 6.17.10-1
    • 6.17.11-1
    • 6.17.12-1
    • 6.17.13-1
    • 6.17.13-1~bpo13+1
    • 6.17.2-1~exp1
    • 6.17.5-1~exp1
    • 6.17.6-1
    • 6.17.7-1
    • 6.17.7-2
    • 6.17.8-1
    • 6.17.8-1~bpo13+1
    • 6.17.9-1
    • 6.18.1-1~exp1
    • 6.18.10-1
    • 6.18.12-1
    • 6.18.12-1~bpo13+1
    • 6.18.13-1
    • 6.18.14-1
    • 6.18.15-1
    • 6.18.15-1~bpo13+1
    • 6.18.2-1~exp1
    • 6.18.3-1
    • 6.18.5-1
    • 6.18.5-1~bpo13+1
    • 6.18.8-1
    • 6.18.9-1
    • 6.18.9-1~bpo13+1
    • 6.18~rc4-1~exp1
    • 6.18~rc4-1~exp2
    • 6.18~rc5-1~exp1
    • 6.18~rc6-1~exp1
    • 6.18~rc7-1~exp1
    • 6.19-1~exp1
    • 6.19.10-1
    • 6.19.10-1~bpo13+1
    • 6.19.11-1
    • 6.19.11-1~bpo13+1
    • 6.19.12-1
    • 6.19.13-1
    • 6.19.13-1~bpo13+1
    • 6.19.14-1
    • 6.19.14-1~bpo13+1
    • 6.19.2-1~exp1
    • 6.19.3-1~exp1
    • 6.19.4-1~exp1
    • 6.19.5-1~exp1
    • 6.19.6-1
    • 6.19.6-2
    • 6.19.6-2~bpo13+1
    • 6.19.8-1
    • 6.19.8-1~bpo13+1
    • 6.19~rc4-1~exp1
    • 6.19~rc5-1~exp1
    • 6.19~rc6-1~exp1
    • 6.19~rc7-1~exp1
    • 6.19~rc8-1~exp1
    • 7.0-1~exp1
    • 7.0.1-1~exp1
    • 7.0.10-1
    • 7.0.10-1~bpo13+1
    • 7.0.12-1
    • 7.0.12-2
    • 7.0.12-2~bpo13+1
    • 7.0.13-1
    • 7.0.13-1~bpo13+1
    • 7.0.14-1
    • 7.0.3-1
    • 7.0.4-1
    • 7.0.4-1~bpo13+1
    • 7.0.7-1
    • 7.0.7-1~bpo13+1
    • 7.0.9-1
    • 7.0.9-1~bpo13+1
    • 7.1.1-1~exp1
    • 7.1.10-1
    • 7.1.12-1
    • 7.1.13-1
    • 7.1.13-1~bpo13+1
    • 7.1.2-1~exp1
    • 7.1.3-1
    • 7.1.3-1+sunvdc
    • 7.1.3-1~bpo13+1
    • 7.1.4-1
    • 7.1.5-1
    • 7.1.6-1
    • 7.1.7-1
    • 7.1.7-1~bpo13+1
    • 7.1.8-1
    • 7.1.8-1~bpo13+1
    • 7.1.8-2
    • 7.1.9-1
    • 7.1.9-1+sparc64
    • 7.1~rc2-1~exp1
    • 7.1~rc3-1~exp1
    • 7.1~rc4-1~exp1
    • 7.1~rc4-1~exp2
    • 7.1~rc5-1~exp1
    • 7.1~rc7-1~exp1
    • 7.2.10-1
    • 7.2.2-1~exp1
    • 7.2.3-1~exp1
    • 7.2.6-1
    • 7.2.6-1~bpo13+1
    • 7.2.7-1
    • 7.2.8-1
    • 7.2.9-1
    • 7.2.9-1~bpo13+1
    • 7.2~rc3-1~exp1
    • 7.2~rc5-1~exp1
    • 7.2~rc7-1~exp1
    Affected ranges
    • ECOSYSTEM: < 7.2.11-1

    Update to 7.2.11-1

Original sources

Check your server →