CVEvulnerability
CVE-2025-38282
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2025-07-10
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
kernfs: Relax constraint in draining guard
The active reference lifecycle provides the break/unbreak mechanism but
the active reference is not truly active after unbreak -- callers don't
use it afterwards but it's important for proper pairing of kn->active
counting. Assuming this mechanism is in place, the WARN check in
kernfs_should_drain_open_files() is too sensitive -- it may transiently
catch those (rightful) callers between
kernfs_unbreak_active_protection() and kernfs_put_active() as found out by Chen
Ridong:
kernfs_remove_by_name_ns kernfs_get_active // active=1
__kernfs_remove // active=0x80000002
kernfs_drain ...
wait_event
//waiting (active == 0x80000001)
kernfs_break_active_protection
// active = 0x80000001
// continue
kernfs_unbreak_active_protection
// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
kernfs_put_active
To avoid the false positives (mind panic_on_warn) remove the check altogether.
(This is meant as quick fix, I think active reference break/unbreak may be
simplified with larger rework.)
Affected configurations
• linux linux kernel (>= 6.1 < 6.1.142)
• linux linux kernel (>= 6.2 < 6.6.94)
• linux linux kernel (>= 6.7 < 6.12.34)
• linux linux kernel (>= 6.13 < 6.15.3)
• debian debian linux 11.0
References
- https://git.kernel.org/stable/c/071d8e4c2a3b0999a9b822e2eb8854784a350f8a Patch
- https://git.kernel.org/stable/c/2d6a67c2b3b87808a347dc1047b520a9dd177a4f Patch
- https://git.kernel.org/stable/c/6bfb154f95d5f0ab7ed056f23aba8c1a94cb3927 Patch
- https://git.kernel.org/stable/c/6c81f1c7812c61f187bed1b938f1d2e391d503ab Patch
- https://git.kernel.org/stable/c/72275c888f8962b406ee9c6885c79bf68cca5a63 Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Mailing List, Third Party Advisory