Re: [Linaro-mm-sig] [PATCH] dma-buf: Fix NULL pointer dereference in sanitycheck()

[Christian König]

Am 20.03.24 um 00:15 schrieb Pavel Sakharov:
> 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>

Going to push it to drm-misc-fixes in a minute.

Thanks,
Christian.

> ---
>   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
>
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