In the Linux kernel, the following vulnerability has been resolved:
pinmux: fix race causing mux_owner NULL with active mux_usecount
commit 5a3e85c3c397 ("pinmux: Use sequential access to access
desc->pinmux data") tried to address the issue when two client of the
same gpio calls pinctrl_select_state() for the same functionality, was
resulting in NULL pointer issue while accessing desc->mux_owner.
However, issue was not completely fixed due to the way it was handled
and it can still result in the same NULL pointer.
The issue occurs due to the following interleaving:
cpu0 (process A) cpu1 (process B)
pin_request() { pin_free() {
mutex_lock()
desc->mux_usecount--; //becomes 0
..
mutex_unlock()
mutex_lock(desc->mux)
desc->mux_usecount++; // becomes 1
desc->mux_owner = owner;
mutex_unlock(desc->mux)
mutex_lock(desc->mux)
desc->mux_owner = NULL;
mutex_unlock(desc->mux)
This sequence leads to a state where the pin appears to be in use
(`mux_usecount == 1`) but has no owner (`mux_owner == NULL`), which can
cause NULL pointer on next pin_request on the same pin.
Ensure that updates to mux_usecount and mux_owner are performed
atomically under the same lock. Only clear mux_owner when mux_usecount
reaches zero and no new owner has been assigned.
References
Configurations
Configuration 1 (hide)
|
History
26 Nov 2025, 17:11
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| CWE | CWE-362 CWE-476 |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 4.7 |
| References | () https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb - Patch | |
| References | () https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9 - Patch | |
| References | () https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787 - Patch | |
| References | () https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564 - Patch | |
| References | () https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 - Patch |
Information
Published : 2025-08-22 16:15
Updated : 2025-11-26 17:11
NVD link : CVE-2025-38632
Mitre link : CVE-2025-38632
CVE.ORG link : CVE-2025-38632
JSON object : View
Products Affected
linux
- linux_kernel