[PATCH RESEND] drm/sti: avoid potential dereference of error pointers

[Alain Volmat]

Hi,

Thanks for your patch.

Acked-by: Alain Volmat <alain.volmat at foss.st.com>

Regards,
Alain

On Mon, Aug 26, 2024 at 01:26:52PM +0800, Ma Ke wrote:
> The return value of drm_atomic_get_crtc_state() needs to be
> checked. To avoid use of error pointer 'crtc_state' in case
> of the failure.
> 
> Cc: stable at vger.kernel.org
> Fixes: dec92020671c ("drm: Use the state pointer directly in planes atomic_check")
> 
> Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
> ---
>  drivers/gpu/drm/sti/sti_cursor.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sti/sti_cursor.c b/drivers/gpu/drm/sti/sti_cursor.c
> index db0a1eb53532..e460f5ba2d87 100644
> --- a/drivers/gpu/drm/sti/sti_cursor.c
> +++ b/drivers/gpu/drm/sti/sti_cursor.c
> @@ -200,6 +200,8 @@ static int sti_cursor_atomic_check(struct drm_plane *drm_plane,
>  		return 0;
>  
>  	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> +	if (IS_ERR(crtc_state))
> +		return PTR_ERR(crtc_state);
>  	mode = &crtc_state->mode;
>  	dst_x = new_plane_state->crtc_x;
>  	dst_y = new_plane_state->crtc_y;
> -- 
> 2.25.1
>