# \[PATCH net\] ip6\_gre: release cached dst on tunnel removal

- Subsystems: NETWORKING \[GENERAL\], NETWORKING \[IPv4/IPv6\], THE REST
- Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
- List: netdev
- 2 messages, 2 authors
- Page: https://ratatoskr.run/netdev/2015/08/10995039/t

## \[PATCH net\] ip6\_gre: release cached dst on tunnel removal

- From: Nicolas Dichtel \<hidden\>
- Date: 2015-08-25 14:21:06 
- Message: https://ratatoskr.run/netdev/2015/08/10995039.md

```text
From: huaibin Wang <redacted>

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 <redacted>
Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
Signed-off-by: huaibin Wang <redacted>
Signed-off-by: Nicolas Dichtel <redacted>
---
 net/ipv6/ip6_gre.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index a38d3ac0f18f..69f4f689f06a 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -361,6 +361,7 @@ static void ip6gre_tunnel_uninit(struct net_device *dev)
 	struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
 
 	ip6gre_tunnel_unlink(ign, t);
+	ip6_tnl_dst_reset(t);
 	dev_put(dev);
 }
 
-- 
2.4.2
```

## Re: \[PATCH net\] ip6\_gre: release cached dst on tunnel removal

- From: David Miller \<davem@davemloft.net\>
- Date: 2015-08-25 21:34:02 
- Message: https://ratatoskr.run/netdev/2015/08/10995104.md

```text
From: Nicolas Dichtel <redacted>
Date: Tue, 25 Aug 2015 16:20:34 +0200

> From: huaibin Wang <redacted>
> 
> 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 <redacted>
> Fixes: c12b395a4664 ("gre: Support GRE over IPv6")
> Signed-off-by: huaibin Wang <redacted>
> Signed-off-by: Nicolas Dichtel <redacted>

Applied and queued up for -stable, thanks.
```