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 <pab...@redhat.com> -- v1 -> v2 droped the route related bits, the fib_validate_source() failures are triggered by the in_device configuration --- net/ipv4/udp.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 836abe5..08eed5e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2070,10 +2070,14 @@ void udp_v4_early_demux(struct sk_buff *skb) 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) { -- 1.8.3.1