Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753574Ab1BBBE3 (ORCPT ); Tue, 1 Feb 2011 20:04:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:4194 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753020Ab1BBAnu (ORCPT ); Tue, 1 Feb 2011 19:43:50 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,412,1291622400"; d="scan'208";a="653504978" From: Andi Kleen References: <20110201443.618138584@firstfloor.org> In-Reply-To: <20110201443.618138584@firstfloor.org> To: davem@davemloft.net, ak@linux.intel.com, damian@tvk.rwth-aachen.de, eric.dumazet@gmail.com, gregkh@suse.de, linux-kernel@vger.kernel.org, stable@kernel.org Subject: [PATCH] [45/139] tcp: Don't change unlocked socket state in tcp_v4_err(). Message-Id: <20110202004400.DD5893E09BD@tassilo.jf.intel.com> Date: Tue, 1 Feb 2011 16:44:00 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2280 Lines: 62 2.6.35-longterm review patch. If anyone has any objections, please let me 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 Signed-off-by: Andi Kleen 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(-) Index: linux-2.6.35.y/net/ipv4/tcp_ipv4.c =================================================================== --- linux-2.6.35.y.orig/net/ipv4/tcp_ipv4.c +++ linux-2.6.35.y/net/ipv4/tcp_ipv4.c @@ -411,6 +411,9 @@ 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; @@ -425,11 +428,6 @@ 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/