Re: [PATCH] firmware: arm_scmi: Fix NULL dereference on notify error path

From: Dan Carpenter

Date: Thu Mar 05 2026 - 10:21:12 EST


On Thu, Mar 05, 2026 at 01:10:11PM +0000, Cristian Marussi wrote:
> Since commit b5daf93b809d1 ("firmware: arm_scmi: Avoid notifier
> registration for unsupported events") the call chains leading to the helper
> __scmi_event_handler_get_ops expect an ERR_PTR to be returned on failure to
> get an handler for the requested event key, while the current helper can
> still return a NULL when no handler could be found or created.
>
> Fix by forcing an ERR_PTR return value when the handler reference is NULL.
>
> Fixes: b5daf93b809d1 ("firmware: arm_scmi: Avoid notifier registration for unsupported events")
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---

Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

I feel a bit bad about this. I saw this as a Smatch warning last August
but I somehow marked it as a false positive. :/

regards,
dan carpenter