ip_tunnel: Initialize the fallback device properly

We need to initialize the fallback device to have a correct mtu
set on this device. Otherwise the mtu is set to null and the device
is unusable.

Fixes: fd58156e456d ("IPIP: Use ip-tunneling code.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 49721d78df75..2acc2337d38b 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -883,6 +883,7 @@ int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
          */
         if (!IS_ERR(itn->fb_tunnel_dev)) {
                 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+                itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev);
                 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev));
         }
         rtnl_unlock();