[PATCH net] adding missing rcu_read_unlock in ipxip6_rcv

[Nikita V. Shirokov]

commit 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels")
introduced new exit point in  ipxip6_rcv. however rcu_read_unlock is
missing there. this diff is fixing this

Signed-off-by: Nikita V. Shirokov <tehn...@fb.com>
---
 net/ipv6/ip6_tunnel.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 3d3092a..00f2c79 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -903,8 +903,10 @@ static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
                        goto drop;
                if (t->parms.collect_md) {
                        tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
-                       if (!tun_dst)
+                       if (!tun_dst) {
+                               rcu_read_unlock();
                                return 0;
+                       }
                }
                ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
                                    log_ecn_error);
-- 
2.9.5