From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934291AbdKAVqR (ORCPT ); Wed, 1 Nov 2017 17:46:17 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:35354 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934207AbdKAV2R (ORCPT ); Wed, 1 Nov 2017 17:28:17 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: WANG Cong , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 081/139] tcp: reset sk_rx_dst in tcp_disconnect() Date: Wed, 1 Nov 2017 22:26:22 +0100 Message-Id: <1509571600-4858-32-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1509571600-4858-1-git-send-email-w@1wt.eu> References: <1509571159-4405-1-git-send-email-w@1wt.eu> <1509571600-4858-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: WANG Cong commit d747a7a51b00984127a88113cdbbc26f91e9d815 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: 41063e9dd119 ("ipv4: Early TCP socket demux.") Reported-by: Andrei Vagin Reported-by: Kevin Xu Signed-off-by: Cong Wang Signed-off-by: David S. Miller [wt: adjusted context] Signed-off-by: Willy Tarreau --- net/ipv4/tcp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index d1e0422..446dc4f 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2316,6 +2316,8 @@ 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); -- 2.8.0.rc2.1.gbe9624a