From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933477Ab2AJXSb (ORCPT ); Tue, 10 Jan 2012 18:18:31 -0500 Received: from cantor2.suse.de ([195.135.220.15]:52401 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933846Ab2AJXAs (ORCPT ); Tue, 10 Jan 2012 18:00:48 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Jan 10 13:50:24 2012 Message-Id: <20120110215023.930621417@clark.kroah.org> User-Agent: quilt/0.50-25.1 Date: Tue, 10 Jan 2012 13:48:45 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Hutchings , "David S. Miller" Subject: [35/42] igmp: Avoid zero delay when receiving odd mixture of IGMP queries In-Reply-To: <20120110215031.GA19398@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings commit a8c1f65c79cbbb2f7da782d4c9d15639a9b94b27 upstream. Commit 5b7c84066733c5dfb0e4016d939757b38de189e4 ('ipv4: correct IGMP behavior on v3 query during v2-compatibility mode') added yet another case for query parsing, which can result in max_delay = 0. Substitute a value of 1, as in the usual v3 case. Reported-by: Simon McVittie References: http://bugs.debian.org/654876 Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- net/ipv4/igmp.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -875,6 +875,8 @@ static void igmp_heard_query(struct in_d * to be intended in a v3 query. */ max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE); + if (!max_delay) + max_delay = 1; /* can't mod w/ 0 */ } else { /* v3 */ if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) return;