CVE Catalog

CVE-2025-38632

MediumCVSS 4.7
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel pinmux subsystem, a race condition between pin_request() and pin_free() can leave a pin with an active use count (mux_usecount) but a NULL owner (mux_owner). This leads to a NULL pointer dereference on the next request for the same pin. The fix ensures atomic updates of mux_usecount and mux_owner under the same lock.

Risk Assessment

The vulnerability can cause a kernel panic or system instability when two GPIO clients concurrently access the same pin, resulting in a denial of service (DoS).

Recommendation

Update the Linux kernel to a version containing the fix (commit 5a3e85c3c397 or later) and deploy it on all systems exposed to concurrent pinmux operations.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS