net: igmp: fix source address check for IGMPv3 reports

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 <cernekee@chromium.org>
Fixes: a46182b00290 ("net: igmp: Use correct source address on IGMPv3 reports")
Reported-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 726f6b6082748896686ae603546fa189348f9142..2d49717a742107eddd4ea31ce418d260146efe19 100644 (file)
--- 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);