Subject: [PATCH 08/37] net: igmp: fix source address check for IGMPv3 reports

From: Felix Fietkau <[email-masked]>
Date: Fri, 19 Jan 2018 11:50:46 +0100

[ Upstream commit ad23b750933ea7bf962678972a286c78a8fa36aa ]

Commit "net: igmp: Use correct source address on IGMPv3 reports"
introduced a check to validate the source address of locally generated
IGMPv3 packets.
Instead of checking the local interface address directly, it uses
inet_ifa_match(fl4->saddr, ifa), which checks if the address is on the
local subnet (or equal to the point-to-point address if used).

This breaks for point-to-point interfaces, so check against
ifa->ifa_local directly.

Cc: Kevin Cernekee <[email-masked]>
Fixes: a46182b00290 ("net: igmp: Use correct source address on IGMPv3 reports")
Reported-by: Sebastian Gottschall <[email-masked]>
Signed-off-by: Felix Fietkau <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/ipv4/igmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index c621266e0306..013fed55b610 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -332,7 +332,7 @@ static __be32 igmpv3_get_srcaddr(struct net_device *dev,
 		return htonl(INADDR_ANY);
 
 	for_ifa(in_dev) {
-		if (inet_ifa_match(fl4->saddr, ifa))
+		if (fl4->saddr == ifa->ifa_local)
 			return fl4->saddr;
 	} endfor_ifa(in_dev);
 
-- 
2.14.3