Commit 00ae1491 authored by Dan Carpenter's avatar Dan Carpenter Committed by Sumit Semwal
Browse files

dma-buf: fix an error pointer vs NULL bug 



Smatch detected potential error pointer dereference.

    drivers/gpu/drm/drm_syncobj.c:888 drm_syncobj_transfer_to_timeline()
    error: 'fence' dereferencing possible ERR_PTR()

The error pointer comes from dma_fence_allocate_private_stub().  One
caller expected error pointers and one expected NULL pointers.  Change
it to return NULL and update the caller which expected error pointers,
drm_syncobj_assign_null_handle(), to check for NULL instead.

Fixes: f781f661 ("dma-buf: keep the signaling time of merged fences v3")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b09f1996-3838-4fa2-9193-832b68262e43@moroto.mountain
parent 7f34e01f

drivers/dma-buf/dma-fence.c

+1 −1
Original line number Diff line number Diff line
@@ -160,7 +160,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp) 


	fence = kzalloc(sizeof(*fence), GFP_KERNEL);

	if (fence == NULL)

		return ERR_PTR(-ENOMEM);

		return NULL;



	dma_fence_init(fence,

		       &dma_fence_stub_ops,

drivers/gpu/drm/drm_syncobj.c

+2 −2
Original line number Diff line number Diff line
@@ -355,8 +355,8 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) 
{

	struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());



	if (IS_ERR(fence))

		return PTR_ERR(fence);

	if (!fence)

		return -ENOMEM;



	drm_syncobj_replace_fence(syncobj, fence);

	dma_fence_put(fence);