CVE-2026-72395: hwmon: (pmbus) Fix passing events to regulator core

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (pmbus) Fix passing events to regulator core

Sashiko reports:

Commit 754bd2b4a084 ("hwmon: (pmbus/core) Protect regulator operations with mutex") introduced a worker to batch regulator events over time using atomicor(). The delayed worker then passes the combined bitmask unmodified to regulatornotifiercallchain().

The core regulator subsystem's regulatorhandlecritical() function evaluates the event parameter using a strict switch statement. If multiple distinct faults occur before the worker runs (e.g., REGULATOREVENTUNDERVOLTAGE | REGULATOREVENTOVERCURRENT), the combined bitmask fails to match any case. This leaves the reason as NULL and completely bypasses the critical hwprotectiontrigger().

Fix the problem by passing events bit by bit to the regulator event handler.