CVEvulnerability
CVE-2025-68788
- Status
- Deferred
- Published
- 2026-01-13
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Weaknesses
- CWE-200
Description
In the Linux kernel, the following vulnerability has been resolved:
fsnotify: do not generate ACCESS/MODIFY events on child for special files
inotify/fanotify do not allow users with no read access to a file to
subscribe to events (e.g. IN_ACCESS/IN_MODIFY), but they do allow the
same user to subscribe for watching events on children when the user
has access to the parent directory (e.g. /dev).
Users with no read access to a file but with read access to its parent
directory can still stat the file and see if it was accessed/modified
via atime/mtime change.
The same is not true for special files (e.g. /dev/null). Users will not
generally observe atime/mtime changes when other users read/write to
special files, only when someone sets atime/mtime via utimensat().
Align fsnotify events with this stat behavior and do not generate
ACCESS/MODIFY events to parent watchers on read/write of special files.
The events are still generated to parent watchers on utimensat(). This
closes some side-channels that could be possibly used for information
exfiltration [1].
[1] https://snee.la/pdf/pubs/file-notification-attacks.pdf
Related
Weakness · CWE (1)
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness
References
- https://git.kernel.org/stable/c/635bc4def026a24e071436f4f356ea08c0eed6ff git.kernel.org
- https://git.kernel.org/stable/c/6a7d7d96eeeab7af2bd01afbb3d9878a11a13d91 git.kernel.org
- https://git.kernel.org/stable/c/7a93edb23bcf07a3aaf8b598edfc2faa8fbcc0b6 git.kernel.org
- https://git.kernel.org/stable/c/82f7416bcbd951549e758d15fc1a96a5afc2e900 git.kernel.org
- https://git.kernel.org/stable/c/859bdf438f01d9aa7f84b09c1202d548c7cad9e8 git.kernel.org
- https://git.kernel.org/stable/c/df2711544b050aba703e6da418c53c7dc5d443ca git.kernel.org
- https://git.kernel.org/stable/c/e0643d46759db8b84c0504a676043e5e341b6c81 git.kernel.org
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html cert-portal.siemens.com
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html cert-portal.siemens.com