cbcvebase.
CVE-2025-21654
published 2025-01-19

CVE-2025-21654: In the Linux kernel, the following vulnerability has been resolved: ovl: support encoding fid from inode with no alias Dmitry Safonov reported that a WARN_ON()…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.20%
9.9th percentile
In the Linux kernel, the following vulnerability has been resolved: ovl: support encoding fid from inode with no alias Dmitry Safonov reported that a WARN_ON() assertion can be trigered by userspace when calling inotify_show_fdinfo() for an overlayfs watched inode, whose dentry aliases were discarded with drop_caches. The WARN_ON() assertion in inotify_show_fdinfo() was removed, because it is possible for encoding file handle to fail for other reason, but the impact of failing to encode an overlayfs file handle goes beyond this assertion. As shown in the LTP test case mentioned in the link below, failure to encode an overlayfs file handle from a non-aliased inode also leads to failure to report an fid with FAN_DELETE_SELF fanotify events. As Dmitry notes in his analyzis of the problem, ovl_encode_fh() fails if it cannot find an alias for the inode, but this failure can be fixed. ovl_encode_fh() seldom uses the alias and in the case of non-decodable file handles, as is often the case with fanotify fid info, ovl_encode_fh() never needs to use the alias to encode a file handle. Defer finding an alias until it is actually needed so ovl_encode_fh() will not fail in the common case of FAN_DELETE_SELF fanotify events.

Affected

11 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.10-1 (forky)linux 6.12.10-1 (forky)
linuxlinux
linuxlinux>= 16aac5ad1fa94894b798dd522c5c3a6a0628d7f0 < f0c0ac84de17c37e6e84da65fb920f91dada55adf0c0ac84de17c37e6e84da65fb920f91dada55ad
linuxlinux>= 16aac5ad1fa94894b798dd522c5c3a6a0628d7f0 < 3c7c90274ae339e1ad443c9be1c67a20b80b9c763c7c90274ae339e1ad443c9be1c67a20b80b9c76
linuxlinux>= 16aac5ad1fa94894b798dd522c5c3a6a0628d7f0 < c45beebfde34aa71afbc48b2c54cdda623515037c45beebfde34aa71afbc48b2c54cdda623515037
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.10-16.12.10-1
linuxlinux_kernel>= 0 < 6.12.10-16.12.10-1
linuxlinux_kernel>= 0 < 6.8.0-60.636.8.0-60.63
linuxlinux_kernel>= 6.6 < 6.6.746.6.74
linuxlinux_kernel>= 6.7 < 6.12.106.12.10

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.