Re: [PATCH] hwmon: (gpio-fan) fix use-after-free in alarm work

[Guenter Roeck]

On Wed, Aug 19, 2026 at 03:33:17AM +0000, Fan Wu wrote:
> 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.
> 
> Fixes: d6fe1360f42e ("hwmon: add generic GPIO fan driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Assisted-by: Codex:gpt-5.6
> Signed-off-by: Fan Wu <fanwu01@xxxxxxxxxx>

Applied.

Thanks,
Guenter