[PATCH 5.2 015/124] ip6_gre: fix a dst leak in ip6erspan_tunnel_xmit

[Greg Kroah-Hartman]

From: Xin Long <lucien....@gmail.com>

[ Upstream commit 28e486037747c2180470b77c290d4090ad42f259 ]

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....@gmail.com>
Acked-by: William Tu <u9012...@gmail.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 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));