Re: [PATCH v3] AF_ALG: Initialize sg_num_bytes in error code path

[Dmitry Vyukov]

On Fri, Jul 6, 2018 at 9:50 AM, Stephan MÃller <smueller@xxxxxxxxxx> wrote:
> Changes v3:
> * Fix syz testing line

Just in case, the syz test does not have to be in the patch. Just an
email to the syzbot address will do.


> Changes v2:
> * Addition of syz testing line
>
> ---8<---
>
> The RX SGL in processing is already registered with the RX SGL tracking
> list to support proper cleanup. The cleanup code path uses the
> sg_num_bytes variable which must therefore be always initialized, even
> in the error code path.
>
> Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
> Reported-by: syzbot+9c251bdd09f83b92ba95@xxxxxxxxxxxxxxxxxxxxxxxxx
> #syz test: https://github.com/google/kmsan.git master
> ---
>  crypto/af_alg.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/crypto/af_alg.c b/crypto/af_alg.c
> index 49fa8582138b..bd6795ff406a 100644
> --- a/crypto/af_alg.c
> +++ b/crypto/af_alg.c
> @@ -1148,8 +1148,10 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
>
>                 /* make one iovec available as scatterlist */
>                 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
> -               if (err < 0)
> +               if (err < 0) {
> +                       rsgl->sg_num_bytes = 0;
>                         return err;
> +               }
>
>                 /* chain the new scatterlist with previous one */
>                 if (areq->last_rsgl)
> --
> 2.17.1
>
>
>
>
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