[PATCH] drm/syncobj: fix leaking dma_fence in drm_syncobj_query_ioctl

[Lionel Landwerlin]

On 22/07/2019 15:59, Christian König wrote:
> We need to check the context number instead if the previous sequence to detect
> an error and if an error is detected we need to drop the reference to the
> current fence or otherwise would leak it.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>

Fixes: 27b575a9aa2f ("drm/syncobj: add timeline payload query ioctl v6")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

> ---
>   drivers/gpu/drm/drm_syncobj.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 75cb4bb7619e..1438dcb3ebb1 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -1298,14 +1298,14 @@ int drm_syncobj_query_ioctl(struct drm_device *dev, void *data,
>   			struct dma_fence *iter, *last_signaled = NULL;
>   
>   			dma_fence_chain_for_each(iter, fence) {
> -				if (!iter)
> -					break;
> -				dma_fence_put(last_signaled);
> -				last_signaled = dma_fence_get(iter);
> -				if (!to_dma_fence_chain(last_signaled)->prev_seqno)
> +				if (iter->context != fence->context) {
> +					dma_fence_put(iter);
>   					/* It is most likely that timeline has
>   					 * unorder points. */
>   					break;
> +				}
> +				dma_fence_put(last_signaled);
> +				last_signaled = dma_fence_get(iter);
>   			}
>   			point = dma_fence_is_signaled(last_signaled) ?
>   				last_signaled->seqno :