Race Condition in Linux Kernel Due to Unprotected Regulator Operations

CVE-2026-31486

What is CVE-2026-31486?

A flaw in the Linux kernel affects regulator operations associated with PMBus registers, as the functions handling voltage settings lacked appropriate mutex protection. This mismanagement leads to race conditions when concurrent access occurs. The integration of mutex locking directly within these critical functions can result in deadlocks, especially since some callbacks may invoke these operations while already holding the mutex. To mitigate this risk, pmbus_regulator_notify() has been modified to operate through a worker function, processing notifications outside of strict mutex control, thereby utilizing atomic event storage for safer operation. The redesign guarantees that the worker function is initialized upon the regulator’s registration and properly managed during device removal.

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