[PATCH] drm: prime: Potential Oops in drm_gem_map_dma_buf()

[Christian König]

Hi Dan,

Am 28.09.20 um 11:07 schrieb Dan Carpenter:
> This code doesn't check if the call to ->get_sg_table() fails so it
> could dereference an error pointer and Oops.
>
> Fixes: c614d7e66c6a ("drm: remove prime sg_table caching")
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

this patch is based on outdated code, please take a look at current 
drm-misc-next.

The gem_prime_get_sg_table callback was removed from the driver 
functions and the missing error check already fixed.

Regards,
Christian.

> ---
>   drivers/gpu/drm/drm_prime.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index 11fe9ff76fd5..1e2c7ff63f16 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -627,6 +627,9 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
>   	else
>   		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
>   
> +	if (IS_ERR(sgt))
> +		return sgt;
> +
>   	ret = dma_map_sgtable(attach->dev, sgt, dir,
>   			      DMA_ATTR_SKIP_CPU_SYNC);
>   	if (ret) {