From a8c1f65c79cbbb2f7da782d4c9d15639a9b94b27 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 9 Jan 2012 14:06:46 -0800 Subject: [PATCH] igmp: Avoid zero delay when receiving odd mixture of IGMP queries 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(+) diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index fa057d105bef..5104bc0bbdbe 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -880,6 +880,8 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, * 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; -- 2.20.1