[PATCH] drm/nouveau: fix dma_address check for CPU/GPU sync

[Ondrej Zary]

On Monday 14 June 2021 13:05:17 Christian König wrote:
> AGP for example doesn't have a dma_address array.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>

Fixes NULL pointer dereference in nouveau_bo_sync_for_device on AGP cards.

Tested-by: Ondrej Zary <linux at zary.sk>

> ---
>  drivers/gpu/drm/nouveau/nouveau_bo.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
> index 3e09df0472ce..170aba99a110 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_bo.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
> @@ -546,7 +546,7 @@ nouveau_bo_sync_for_device(struct nouveau_bo *nvbo)
>  	struct ttm_tt *ttm_dma = (struct ttm_tt *)nvbo->bo.ttm;
>  	int i, j;
>  
> -	if (!ttm_dma)
> +	if (!ttm_dma || !ttm_dma->dma_address)
>  		return;
>  	if (!ttm_dma->pages) {
>  		NV_DEBUG(drm, "ttm_dma 0x%p: pages NULL\n", ttm_dma);
> @@ -582,7 +582,7 @@ nouveau_bo_sync_for_cpu(struct nouveau_bo *nvbo)
>  	struct ttm_tt *ttm_dma = (struct ttm_tt *)nvbo->bo.ttm;
>  	int i, j;
>  
> -	if (!ttm_dma)
> +	if (!ttm_dma || !ttm_dma->dma_address)
>  		return;
>  	if (!ttm_dma->pages) {
>  		NV_DEBUG(drm, "ttm_dma 0x%p: pages NULL\n", ttm_dma);


-- 
Ondrej Zary