fsnotify: do not generate ACCESS/MODIFY events on child for special files (Linux Linux)

CVE-2025-68788
Not available

At a glance

Source
NVD
EPSS
EPSS 0.27 % · percentile 20 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Deferred

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

Weaknesses (CWE)

  • CWE-200 — Exposure of Sensitive Information to an Unauthorized Actor

References

European references

CERT-FR advisories

Affected products

ProductVersions
Linux · Linuxaffected 72acc854427948efed7a83da27f7dc3239ac9afc < df2711544b050aba703e6da418c53c7dc5d443ca ; affected 72acc854427948efed7a83da27f7dc3239ac9afc < 859bdf438f01d9aa7f84b09c1202d548c7cad9e8 ; affected 72acc854427948efed7a83da27f7dc3239ac9afc < 6a7d7d96eeeab7af2bd01afbb3d9878a11a13d91 ; affected 72acc854427948efed7a83da27f7dc3239ac9afc < e0643d46759db8b84c0504a676043e5e341b6c81 ; affected 72acc854427948efed7a83da27f7dc3239ac9afc < 82f7416bcbd951549e758d15fc1a96a5afc2e900 ; affected 72acc854427948efed7a83da27f7dc3239ac9afc < 7a93edb23bcf07a3aaf8b598edfc2faa8fbcc0b6
Linux · Linuxaffected 2.6.36 ; unaffected 0 < 2.6.36 ; unaffected 5.10.248 ≤ 5.10.* ; unaffected 5.15.198 ≤ 5.15.* ; unaffected 6.1.160 ≤ 6.1.* ; unaffected 6.6.120 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD