Re: [PATCH] drm/i915: Fix NULL ptr deref in intel_async_flip_check_uapi()

[Andi Shyti]

Hi Ma,

> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index c2c388212e2e..9dd7b5985d57 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6115,7 +6115,7 @@ static int intel_async_flip_check_uapi(struct intel_atomic_state *state,
>  		return -EINVAL;
>  	}
>  
> -	if (intel_crtc_needs_modeset(new_crtc_state)) {
> +	if (new_crtc_state && intel_crtc_needs_modeset(new_crtc_state)) {

new_crtc_state is used also earlier. If it was NULL you wouldn't
have reached this state.

Have you experienced a null pointer dereference or is it some
code analyzer that reported this? Can you explain how
intel_atomic_get_new_crtc_state() can return NULL?

For now this is nacked.

Thanks,
Andi