diff options
| author | Hyejeong Choi <hjeong.choi@samsung.com> | 2025-05-12 21:06:38 -0500 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2025-05-14 15:31:23 +0200 |
| commit | 72c7d62583ebce7baeb61acce6057c361f73be4a (patch) | |
| tree | 73e9d5704208aab3be9a6acf5c8ecfdc9047fdb7 | |
| parent | 2f0c6fceae0df59a9c0edb5d41529b90ee9f2fcb (diff) | |
dma-buf: insert memory barrier before updating num_fences
smp_store_mb() inserts memory barrier after storing operation.
It is different with what the comment is originally aiming so Null
pointer dereference can be happened if memory update is reordered.
Signed-off-by: Hyejeong Choi <hjeong.choi@samsung.com>
Fixes: a590d0fdbaa5 ("dma-buf: Update reservation shared_count after adding the new fence")
CC: stable@vger.kernel.org
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20250513020638.GA2329653@au1-maretx-p37.eng.sarc.samsung.com
Signed-off-by: Christian König <christian.koenig@amd.com>
| -rw-r--r-- | drivers/dma-buf/dma-resv.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 5f8d010516f0..b1ef4546346d 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -320,8 +320,9 @@ void dma_resv_add_fence(struct dma_resv *obj, struct dma_fence *fence, count++; dma_resv_list_set(fobj, i, fence, usage); - /* pointer update must be visible before we extend the num_fences */ - smp_store_mb(fobj->num_fences, count); + /* fence update must be visible before we extend the num_fences */ + smp_wmb(); + fobj->num_fences = count; } EXPORT_SYMBOL(dma_resv_add_fence); |