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.sakha...@ispras.ru> --- drivers/dma-buf/st-dma-fence-chain.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c index 9c2a0c082a76..ed4b323886e4 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); -- 2.44.0