Patch "vxlan: fix oops in dev_fill_metadata_dst" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    vxlan: fix oops in dev_fill_metadata_dst

to the 4.9-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:
     vxlan-fix-oops-in-dev_fill_metadata_dst.patch
and it can be found in the queue-4.9 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 Thu Feb 23 21:13:05 CET 2017
From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 17 Feb 2017 19:14:27 +0100
Subject: vxlan: fix oops in dev_fill_metadata_dst

From: Paolo Abeni <pabeni@redhat.com>


[ Upstream commit 22f0708a718daea5e79de2d29b4829de016a4ff4 ]

Since the commit 0c1d70af924b ("net: use dst_cache for vxlan device")
vxlan_fill_metadata_dst() calls vxlan_get_route() passing a NULL
dst_cache pointer, so the latter should explicitly check for
valid dst_cache ptr. Unfortunately the commit d71785ffc7e7 ("net: add
dst_cache to ovs vxlan lwtunnel") removed said check.

As a result is possible to trigger a null pointer access calling
vxlan_fill_metadata_dst(), e.g. with:

ovs-vsctl add-br ovs-br0
ovs-vsctl add-port ovs-br0 vxlan0 -- set interface vxlan0 \
	type=vxlan options:remote_ip=192.168.1.1 \
	options:key=1234 options:dst_port=4789 ofport_request=10
ip address add dev ovs-br0 172.16.1.2/24
ovs-vsctl set Bridge ovs-br0 ipfix=@i -- --id=@i create IPFIX \
	targets=\"172.16.1.1:1234\" sampling=1
iperf -c 172.16.1.1 -u -l 1000 -b 10M -t 1 -p 1234

This commit addresses the issue passing to vxlan_get_route() the
dst_cache already available into the lwt info processed by
vxlan_fill_metadata_dst().

Fixes: d71785ffc7e7 ("net: add dst_cache to ovs vxlan lwtunnel")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/vxlan.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2449,7 +2449,8 @@ static int vxlan_fill_metadata_dst(struc
 			return -EINVAL;
 		rt = vxlan_get_route(vxlan, skb, 0, info->key.tos,
 				     info->key.u.ipv4.dst,
-				     &info->key.u.ipv4.src, NULL, info);
+				     &info->key.u.ipv4.src,
+				     &info->dst_cache, info);
 		if (IS_ERR(rt))
 			return PTR_ERR(rt);
 		ip_rt_put(rt);
@@ -2459,7 +2460,8 @@ static int vxlan_fill_metadata_dst(struc
 
 		ndst = vxlan6_get_route(vxlan, skb, 0, info->key.tos,
 					info->key.label, &info->key.u.ipv6.dst,
-					&info->key.u.ipv6.src, NULL, info);
+					&info->key.u.ipv6.src,
+					&info->dst_cache, info);
 		if (IS_ERR(ndst))
 			return PTR_ERR(ndst);
 		dst_release(ndst);


Patches currently in stable-queue which might be from pabeni@redhat.com are

queue-4.9/ip-fix-ip_checksum-handling.patch
queue-4.9/vxlan-fix-oops-in-dev_fill_metadata_dst.patch