CVE-2025-38632

/// Technical description

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 =

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References