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: f781f661e8 ("dma-buf: keep the signaling time of merged fences v3")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b09f1996-3838-4fa2-9193-832b68262e43@moroto.mountain
This commit is contained in:
Dan Carpenter 2023-07-06 15:37:51 +03:00 committed by Sumit Semwal
parent 7f34e01f77
commit 00ae1491f9
2 changed files with 3 additions and 3 deletions

View File

@ -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,

View File

@ -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);