Re: [PATCH net] tcp: fix forever orphan socket caused by tcp_abort

From: Jason Xing
Date: Tue Aug 06 2024 - 07:34:57 EST


[...]
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index e03a342c9162..831a18dc7aa6 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -4637,6 +4637,13 @@ int tcp_abort(struct sock *sk, int err)
> /* Don't race with userspace socket closes such as tcp_close. */
> lock_sock(sk);
>
> + /* Avoid closing the same socket twice. */
> + if (sk->sk_state == TCP_CLOSE) {
> + if (!has_current_bpf_ctx())
> + release_sock(sk);
> + return -ENOENT;

I'm not quite sure about this.

> + }
> +
> if (sk->sk_state == TCP_LISTEN) {
> tcp_set_state(sk, TCP_CLOSE);
> inet_csk_listen_stop(sk);
> @@ -4646,16 +4653,13 @@ int tcp_abort(struct sock *sk, int err)
> local_bh_disable();
> bh_lock_sock(sk);
>
> - if (!sock_flag(sk, SOCK_DEAD)) {
> - if (tcp_need_reset(sk->sk_state))
> - tcp_send_active_reset(sk, GFP_ATOMIC,
> - SK_RST_REASON_NOT_SPECIFIED);
> - tcp_done_with_error(sk, err);
> - }
> + if (tcp_need_reset(sk->sk_state))
> + tcp_send_active_reset(sk, GFP_ATOMIC,
> + SK_RST_REASON_NOT_SPECIFIED);
> + tcp_done_with_error(sk, err);
>
> bh_unlock_sock(sk);
> local_bh_enable();
> - tcp_write_queue_purge(sk);

On the whole, it looks fine to me. Please let maintainer take a look
at it finally.

Thanks!