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

[Alain Volmat]

Hi,

Thank you for your patch.

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

Regards,
Alain

On Mon, Sep 09, 2024 at 02:33:59PM +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: dd86dc2f9ae1 ("drm/sti: implement atomic_check for the planes")
> Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
> ---
>  drivers/gpu/drm/sti/sti_gdp.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sti/sti_gdp.c b/drivers/gpu/drm/sti/sti_gdp.c
> index 43c72c2604a0..f046f5f7ad25 100644
> --- a/drivers/gpu/drm/sti/sti_gdp.c
> +++ b/drivers/gpu/drm/sti/sti_gdp.c
> @@ -638,6 +638,9 @@ static int sti_gdp_atomic_check(struct drm_plane *drm_plane,
>  
>  	mixer = to_sti_mixer(crtc);
>  	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
>