ip6_tunnel: copy parms.name after register_netdevice

commit 731abb9cb27aef6013ce60808a04e04a545f3f4e upstream.

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.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 0bc98886c383c93c79e81a3cd7c4bfe220502b58..4e6922f1c68720b37b877a58b3d95b00a52552f5 100644 (file)
--- 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;
@@ -1397,7 +1399,6 @@ 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;
@@ -1477,6 +1478,7 @@ 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;
@@ -1497,6 +1499,10 @@ 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: