Re: [syzbot] WARNING in sk_stream_kill_queues (8)

[Stanislav Fomichev]

On Thu, Jul 7, 2022 at 11:39 AM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:
>
> On Wed, Jul 6, 2022 at 9:40 AM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:
> >
> > I will look into this tonight.
>
> The following patch could work. It uncharges the sk mem before passing skb
> to recv actor but still keeps skb->sk.

This seems to make syzkaller happy.

Tested-by: Stanislav Fomichev <sdf@xxxxxxxxxx>

> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 9d2fd3ced21b..c6b1effb2afd 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -1749,6 +1749,7 @@ int tcp_read_skb(struct sock *sk,
> skb_read_actor_t recv_actor)
>                 int used;
>
>                 __skb_unlink(skb, &sk->sk_receive_queue);
> +               WARN_ON(!skb_set_owner_sk_safe(skb, sk));
>                 used = recv_actor(sk, skb);
>                 if (used <= 0) {
>                         if (!copied)