4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Paolo Abeni <[email protected]> [ 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 <[email protected]> Acked-by: Jiri Benc <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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);
