ip6_tunnel: copy parms.name after register_netdevice

Commit 1c5cae815d removed an explicit call to dev_alloc_name in ip6_tnl_create
because register_netdevice will now create a valid name.  This works for the
net_device itself.

However the tunnel keeps a copy of the name in the parms structure for the
ip6_tnl associated with the tunnel.  parms.name is set by copying the net_device
name in ip6_tnl_dev_init_gen.  That function is called from ip6_tnl_dev_init in
ip6_tnl_create, but it is done before register_netdevice is called so the name
is set to a bogus value in the parms.name structure.

This shows up if you do a simple tunnel add, followed by a tunnel show:

[root@localhost ~]# ip -6 tunnel add remote fec0::100 local fec0::200
[root@localhost ~]# ip -6 tunnel show
ip6tnl0: ipv6/ipv6 remote :: local :: encaplimit 0 hoplimit 0 tclass 0x00 flowlabel 0x00000 (flowinfo 0x00000000)
ip6tnl%d: ipv6/ipv6 remote fec0::100 local fec0::200 encaplimit 4 hoplimit 64 tclass 0x00 flowlabel 0x00000 (flowinfo 0x00000000)
[root@localhost ~]#

Fix this by moving the strcpy out of ip6_tnl_dev_init_gen, and calling it after
register_netdevice has successfully returned.

Cc: stable@vger.kernel.org
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 1 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index bdc15c9003d7..4e2e9ff67ef2 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -289,6 +289,8 @@ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p)
         if ((err = register_netdevice(dev)) < 0)
                 goto failed_free;
 
+        strcpy(t->parms.name, dev->name);
+
         dev_hold(dev);
         ip6_tnl_link(ip6n, t);
         return t;
@@ -1407,7 +1409,6 @@ ip6_tnl_dev_init_gen(struct net_device *dev)
         struct ip6_tnl *t = netdev_priv(dev);
 
         t->dev = dev;
-        strcpy(t->parms.name, dev->name);
         dev->tstats = alloc_percpu(struct pcpu_tstats);
         if (!dev->tstats)
                 return -ENOMEM;
@@ -1487,6 +1488,7 @@ static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
 static int __net_init ip6_tnl_init_net(struct net *net)
 {
         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
+        struct ip6_tnl *t = NULL;
         int err;
 
         ip6n->tnls[0] = ip6n->tnls_wc;
@@ -1507,6 +1509,10 @@ static int __net_init ip6_tnl_init_net(struct net *net)
         err = register_netdev(ip6n->fb_tnl_dev);
         if (err < 0)
                 goto err_register;
+
+        t = netdev_priv(ip6n->fb_tnl_dev);
+
+        strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
         return 0;
 
 err_register: