From: Xin Long <lucien.xin@gmail.com>
Date: Fri, 13 Sep 2019 17:45:47 +0800
Subject: ip6_gre: fix a dst leak in ip6erspan_tunnel_xmit
Git-commit: 28e486037747c2180470b77c290d4090ad42f259
Patch-mainline: 5.4-rc1
References: bnc#1151927 5.3.1

In ip6erspan_tunnel_xmit(), if the skb will not be sent out, it has to
be freed on the tx_err path. Otherwise when deleting a netns, it would
cause dst/dev to leak, and dmesg shows:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 net/ipv6/ip6_gre.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -968,7 +968,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit
 		if (unlikely(!tun_info ||
 			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
 			     ip_tunnel_info_af(tun_info) != AF_INET6))
-			return -EINVAL;
+			goto tx_err;
 
 		key = &tun_info->key;
 		memset(&fl6, 0, sizeof(fl6));