From cdd74d6ac80ef50a520b6234947f8e2f6ebca75a Mon Sep 17 00:00:00 2001 From: Miguel Fadon Perlines Date: Thu, 5 Apr 2018 10:25:38 +0200 Subject: [PATCH] arp: fix arp_filter on l3slave devices [ Upstream commit 58b35f27689b5eb514fc293c332966c226b1b6e4 ] arp_filter performs an ip_route_output search for arp source address and checks if output device is the same where the arp request was received, if it is not, the arp request is not answered. This route lookup is always done on main route table so l3slave devices never find the proper route and arp is not answered. Passing l3mdev_master_ifindex_rcu(dev) return value as oif fixes the lookup for l3slave devices while maintaining same behavior for non l3slave devices as this function returns 0 in that case. Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX") Signed-off-by: Miguel Fadon Perlines Acked-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/arp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index a1d1f50e0e19..7d9cf26f4bb1 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -437,7 +437,7 @@ static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) /*unsigned long now; */ struct net *net = dev_net(dev); - rt = ip_route_output(net, sip, tip, 0, 0); + rt = ip_route_output(net, sip, tip, 0, l3mdev_master_ifindex_rcu(dev)); if (IS_ERR(rt)) return 1; if (rt->dst.dev != dev) {