Commit 58347335 authored by WANG Cong's avatar WANG Cong Committed by Ben Hutchings

tcp: reset sk_rx_dst in tcp_disconnect()

commit d747a7a5 upstream.

We have to reset the sk->sk_rx_dst when we disconnect a TCP
connection, because otherwise when we re-connect it this
dst reference is simply overridden in tcp_finish_connect().

This fixes a dst leak which leads to a loopback dev refcnt
leak. It is a long-standing bug, Kevin reported a very similar
(if not same) bug before. Thanks to Andrei for providing such
a reliable reproducer which greatly narrows down the problem.

Fixes: 41063e9d ("ipv4: Early TCP socket demux.")
Reported-by: default avatarAndrei Vagin <avagin@gmail.com>
Reported-by: default avatarKevin Xu <kaiwen.xu@hulu.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
parent 59d9b0eb
......@@ -2367,6 +2367,8 @@ int tcp_disconnect(struct sock *sk, int flags)
tcp_init_send_head(sk);
memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
__sk_dst_reset(sk);
dst_release(sk->sk_rx_dst);
sk->sk_rx_dst = NULL;
WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment