CVE-2025-38632

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-38632
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.

4.7 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.0 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb Patch
https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9 Patch
https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787 Patch
https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564 Patch
https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

26 Nov 2025, 17:11

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb - () https://git.kernel.org/stable/c/0b075c011032f88d1cfde3b45d6dcf08b44140eb - Patch
References () https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9 - () https://git.kernel.org/stable/c/22b585cbd67d14df3b91529d1b990661c300faa9 - Patch
References () https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787 - () https://git.kernel.org/stable/c/9b2a3e7189028aa7c4d53a84364f2ea9fb209787 - Patch
References () https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564 - () https://git.kernel.org/stable/c/9ea3f6b9a67be3476e331ce51cac316c2614a564 - Patch
References () https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 - () https://git.kernel.org/stable/c/b7bd6e3971eb7f0e34d2fdce1b18b08094e0c804 - Patch
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: pinmux: corrección de la carrera que causaba que mux_owner fuera nulo con el commit 5a3e85c3c397 de mux_usecount activa ("pinmux: Usar acceso secuencial para acceder a los datos de desc->pinmux"). Se intentó solucionar el problema cuando dos clientes del mismo GPIO llamaban a pinctrl_select_state() para la misma funcionalidad, lo que provocaba un problema de puntero nulo al acceder a desc->mux_owner. Sin embargo, el problema no se solucionó por completo debido a la forma en que se gestionó y aún puede resultar en el mismo puntero nulo. El problema se produce debido a la siguiente intercalación: cpu0 (proceso A) cpu1 (proceso B) pin_request() { pin_free() { mutex_lock() desc->mux_usecount--; //se convierte en 0 .. mutex_unlock() mutex_lock(desc->mux) desc->mux_usecount++; // se convierte en 1 desc->mux_owner = owner; mutex_unlock(desc->mux) mutex_lock(desc->mux) desc->mux_owner = NULL; mutex_unlock(desc->mux) Esta secuencia lleva a un estado donde el pin parece estar en uso (`mux_usecount == 1`) pero no tiene propietario (`mux_owner == NULL`), lo que puede generar un puntero nulo en la siguiente solicitud de pin en el mismo pin. Asegúrese de que las actualizaciones de mux_usecount y mux_owner se realicen automáticamente bajo el mismo bloqueo. Solo borre mux_owner cuando mux_usecount llegue a cero y no se haya asignado un nuevo propietario.
CWE CWE-476
CWE-362
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 4.7

22 Aug 2025, 16:15

Type Values Removed Values Added
New CVE
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
CWE
CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CWE-476

NULL Pointer Dereference