This is a note to let you know that I've just added the patch titled dma-buf: Fix NULL pointer dereference in sanitycheck() to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dma-buf-fix-null-pointer-dereference-in-sanitycheck.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7b1e2551ddaab8cff0996c5150877afa866f9f50 Author: Pavel Sakharov <p.sakharov@xxxxxxxxx> Date: Wed Mar 20 04:15:23 2024 +0500 dma-buf: Fix NULL pointer dereference in sanitycheck() [ Upstream commit 2295bd846765c766701e666ed2e4b35396be25e6 ] If due to a memory allocation failure mock_chain() returns NULL, it is passed to dma_fence_enable_sw_signaling() resulting in NULL pointer dereference there. Call dma_fence_enable_sw_signaling() only if mock_chain() succeeds. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: d62c43a953ce ("dma-buf: Enable signaling on fence for selftests") Signed-off-by: Pavel Sakharov <p.sakharov@xxxxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> Signed-off-by: Christian König <christian.koenig@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240319231527.1821372-1-p.sakharov@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c index 9c2a0c082a768..ed4b323886e43 100644 --- a/drivers/dma-buf/st-dma-fence-chain.c +++ b/drivers/dma-buf/st-dma-fence-chain.c @@ -84,11 +84,11 @@ static int sanitycheck(void *arg) return -ENOMEM; chain = mock_chain(NULL, f, 1); - if (!chain) + if (chain) + dma_fence_enable_sw_signaling(chain); + else err = -ENOMEM; - dma_fence_enable_sw_signaling(chain); - dma_fence_signal(f); dma_fence_put(f);