From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214Ab1AFA3u (ORCPT ); Wed, 5 Jan 2011 19:29:50 -0500 Received: from kroah.org ([198.145.64.141]:35676 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754180Ab1AFA3p (ORCPT ); Wed, 5 Jan 2011 19:29:45 -0500 X-Mailbox-Line: From gregkh@clark.site Wed Jan 5 16:23:01 2011 Message-Id: <20110106002301.699739022@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 05 Jan 2011 16:22:32 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "David S. Miller" , Damian Lukowski , Eric Dumazet Subject: [053/152] tcp: Dont change unlocked socket state in tcp_v4_err(). In-Reply-To: <20110106002500.GA3172@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.36-stable review patch. If anyone has any objections, please let us know. ------------------ From: David S. Miller [ Upstream commit 8f49c2703b33519aaaccc63f571b465b9d2b3a2d ] Alexey Kuznetsov noticed a regression introduced by commit f1ecd5d9e7366609d640ff4040304ea197fbc618 ("Revert Backoff [v3]: Revert RTO on ICMP destination unreachable") The RTO and timer modification code added to tcp_v4_err() doesn't check sock_owned_by_user(), which if true means we don't have exclusive access to the socket and therefore cannot modify it's critical state. Just skip this new code block if sock_owned_by_user() is true and eliminate the now superfluous sock_owned_by_user() code block contained within. Reported-by: Alexey Kuznetsov Signed-off-by: David S. Miller CC: Damian Lukowski Acked-by: Eric Dumazet Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_ipv4.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -415,6 +415,9 @@ void tcp_v4_err(struct sk_buff *icmp_skb !icsk->icsk_backoff) break; + if (sock_owned_by_user(sk)) + break; + icsk->icsk_backoff--; inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) << icsk->icsk_backoff; @@ -429,11 +432,6 @@ void tcp_v4_err(struct sk_buff *icmp_skb if (remaining) { inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, remaining, TCP_RTO_MAX); - } else if (sock_owned_by_user(sk)) { - /* RTO revert clocked out retransmission, - * but socket is locked. Will defer. */ - inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, - HZ/20, TCP_RTO_MAX); } else { /* RTO revert clocked out retransmission. * Will retransmit now */