Patch "arp: fix arp_filter on l3slave devices" has been added to the 4.16-stable tree

Patch "arp: fix arp_filter on l3slave devices" has been added to the 4.16-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arp: fix arp_filter on l3slave devices

to the 4.16-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arp-fix-arp_filter-on-l3slave-devices.patch
and it can be found in the queue-4.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Apr 10 23:19:25 CEST 2018
From: Miguel Fadon Perlines <mfadon@teldat.com>
Date: Thu, 5 Apr 2018 10:25:38 +0200
Subject: arp: fix arp_filter on l3slave devices

From: Miguel Fadon Perlines <mfadon@teldat.com>


[ 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 <mfadon@teldat.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/arp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -437,7 +437,7 @@ static int arp_filter(__be32 sip, __be32
 	/*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) {


Patches currently in stable-queue which might be from mfadon@teldat.com are

queue-4.16/arp-fix-arp_filter-on-l3slave-devices.patch