In the Linux kernel, the following vulnerability has been resolved:
hwmon: (gpio-fan) Fix use-after-free in alarm work
fan_alarm_irq_handler() queues fan_data->alarm_work, but nothing
cancels it. fan_alarm_notify() dereferences fan_data and its hwmon
device. On unbind, devres frees the interrupt, which only waits for
the handler itself, and then releases the hwmon device and fan_data,
so a pending fan_alarm_notify() can run after those frees.
Replace INIT_WORK() with devm_work_autocancel(), registered before
devm_request_irq(). The devres cleanup then frees the interrupt
first, so no new work can be queued, and cancels the work while
fan_data and the hwmon device are still alive.
This issue was found by an in-house static analysis tool.
