CVE-2025-38282
5.5
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploitability: 1.8 / Impact: 3.6
Source: NVD
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 (5)
Products: Linux: Linux Kernel · Debian: Debian Linux
Configuration A
| Vulnerable Software | Affected Versions |
|---|---|
| From 6.1 to 6.1.142 |
Configuration B
| Vulnerable Software | Affected Versions |
|---|---|
| Version 11.0 |
References (6)
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
Source: af854a3a-2127-422b-91ae-364da2661108
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