CVE-2025-38282
kernfs: Relax constraint in draining guard
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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.)
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.)
CVSS Scores
SSVC
- Decision:-
Timeline
- 2025-04-16 CVE Reserved
- 2025-07-10 CVE Published
- 2025-07-10 CVE Updated
- 2025-07-10 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (6)
URL | Tag | Source |
---|---|---|
https://git.kernel.org/stable/c/bdb2fd7fc56e197a63c0b0e7e07d25d5e20e7c72 | Vuln. Introduced |
URL | Date | SRC |
---|
URL | Date | SRC |
---|
Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1 < 6.1.142 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1 < 6.1.142" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1 < 6.6.94 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1 < 6.6.94" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1 < 6.12.34 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1 < 6.12.34" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1 < 6.15.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1 < 6.15.3" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1 < 6.16-rc1 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1 < 6.16-rc1" | en |
Affected
|