ip6_gre: release cached dst on tunnel removal

[ 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: Jiri Slaby <jslaby@suse.cz>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 7d640f276e87e453e6844bee2719de1e69dc3556..b2e4c77d9a8cebfca853debfee118d0e5f788e19 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -360,6 +360,7 @@ static void ip6gre_tunnel_uninit(struct net_device *dev)
        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);
 }