[PATCH 3.14 63/84] ip6_gre: release cached dst on tunnel removal

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: huaibin Wang <huaibin.wang@6wind.com>

[ Upstream commit d4257295ba1b389c693b79de857a96e4b7cd8ac0 ]

When a tunnel is deleted, the cached dst entry should be released.

This problem may prevent the removal of a netns (seen with a x-netns IPv6
gre tunnel):
  unregister_netdevice: waiting for lo to become free. Usage count = 3

CC: Dmitry Kozlov <xeb@mail.ru>
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: huaibin Wang <huaibin.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv6/ip6_gre.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -357,6 +357,7 @@ static void ip6gre_tunnel_uninit(struct
 	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
 
 	ip6gre_tunnel_unlink(ign, netdev_priv(dev));
+	ip6_tnl_dst_reset(netdev_priv(dev));
 	dev_put(dev);
 }