3.16.52-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Abeni <pabeni@xxxxxxxxxx>
commit ad0ea1989cc4d5905941d0a9e62c63ad6d859cef upstream.
Currently, ingress ipv4 broadcast datagrams are dropped since,
in udp_v4_early_demux(), ip_check_mc_rcu() is invoked even on
bcast packets.
This patch addresses the issue, invoking ip_check_mc_rcu()
only for mcast packets.
Fixes: 6e5403093261 ("ipv4/udp: Verify multicast group is ours in upd_v4_early_demux()")
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/ipv4/udp.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1974,10 +1974,14 @@ void udp_v4_early_demux(struct sk_buff *
if (!in_dev)
return;
- ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
- iph->protocol);
- if (!ours)
- return;
+ /* we are supposed to accept bcast packets */
+ if (skb->pkt_type == PACKET_MULTICAST) {
+ ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
+ iph->protocol);
+ if (!ours)
+ return;
+ }
+
sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
uh->source, iph->saddr, dif);
} else if (skb->pkt_type == PACKET_HOST) {