Race Condition in Linux Kernel Pin Multiplexer Affects Multiple Processes

CVE-2025-38632

What is CVE-2025-38632?

A race condition exists in the Linux kernel's pin multiplexer (pinmux) implementation, where simultaneous GPIO requests from different processes can lead to an inconsistent state. This flaw arises from the improper handling of the mux_usecount and mux_owner variables. Specifically, while one process may be decrementing the mux_usecount, another process can erroneously set the mux_owner to NULL. This race scenario can ultimately result in a NULL pointer dereference on subsequent requests, undermining the stability of the system. Proper atomic handling of the mutex locks is required to ensure that the mux_usecount and mux_owner are correctly updated to preserve integrity and prevent access violations.

References