[PATCH net v2] 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

v1->v2:
 instead of doing rcu_read_unlock in place, we are going to "drop"
 section (to prevent skb leakage)

Signed-off-by: Nikita V. Shirokov <tehn...@fb.com>
---
 net/ipv6/ip6_tunnel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 3d3092a..db84f52 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -904,7 +904,7 @@ static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
                if (t->parms.collect_md) {
                        tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
                        if (!tun_dst)
-                               return 0;
+                               goto drop;
                }
                ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
                                    log_ecn_error);
-- 
2.9.5