Am 06.07.23 um 14:37 schrieb Dan Carpenter:
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: f781f661e8c9 ("dma-buf: keep the signaling time of merged fences v3")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Should I push that one to drm-misc-fixes?
Regards,
Christian.
---
v2: Fix it in dma_fence_allocate_private_stub() instead of
__dma_fence_unwrap_merge().
drivers/dma-buf/dma-fence.c | 2 +-
drivers/gpu/drm/drm_syncobj.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index ad076f208760..8aa8f8cb7071 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -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,
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 04589a35eb09..e592c5da70ce 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -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);
