[PATCH 3/4] drm/rockchip: vop2: Don't crash for invalid duplicate_state

[Sascha Hauer]

On Tue, Jun 20, 2023 at 06:47:38AM +0000, Jonas Karlman wrote:
> It's possible for users to try to duplicate the CRTC state even when the
> state doesn't exist. drm_atomic_helper_crtc_duplicate_state() (and other
> users of __drm_atomic_helper_crtc_duplicate_state()) already guard this
> with a WARN_ON() instead of crashing, so let's do that here too.
> 
> Fixes: 604be85547ce ("drm/rockchip: Add VOP2 driver")
> Signed-off-by: Jonas Karlman <jonas at kwiboo.se>

Reviewed-by: Sascha Hauer <s.hauer at pengutronix.de>

Sascha

> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> index ca73b8ccc29f..f725487d02ef 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> @@ -2099,11 +2099,13 @@ static void vop2_crtc_reset(struct drm_crtc *crtc)
>  
>  static struct drm_crtc_state *vop2_crtc_duplicate_state(struct drm_crtc *crtc)
>  {
> -	struct rockchip_crtc_state *vcstate, *old_vcstate;
> +	struct rockchip_crtc_state *vcstate;
>  
> -	old_vcstate = to_rockchip_crtc_state(crtc->state);
> +	if (WARN_ON(!crtc->state))
> +		return NULL;
>  
> -	vcstate = kmemdup(old_vcstate, sizeof(*old_vcstate), GFP_KERNEL);
> +	vcstate = kmemdup(to_rockchip_crtc_state(crtc->state),
> +			  sizeof(*vcstate), GFP_KERNEL);
>  	if (!vcstate)
>  		return NULL;
>  
> -- 
> 2.41.0
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |