[IPV4/IPV6]: Fix inet{,6} device initialization order.

It is important that we only assign dev->ip{,6}_ptr
only after all portions of the inet{,6} are setup.

Otherwise we can receive packets before the multicast
spinlocks et al. are initialized.

Signed-off-by: David L Stevens <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ipv4/devinet.c

···
 			      NET_IPV4_NEIGH, "ipv4", NULL, NULL);
 #endif
 
-	/* Account for reference dev->ip_ptr */
+	/* Account for reference dev->ip_ptr (below) */
 	in_dev_hold(in_dev);
-	rcu_assign_pointer(dev->ip_ptr, in_dev);
 
 #ifdef CONFIG_SYSCTL
 	devinet_sysctl_register(in_dev, &in_dev->cnf);
···
 	if (dev->flags & IFF_UP)
 		ip_mc_up(in_dev);
 out:
+	/* we can receive as soon as ip_ptr is set -- do this last */
+	rcu_assign_pointer(dev->ip_ptr, in_dev);
 	return in_dev;
 out_kfree:
 	kfree(in_dev);

net/ipv6/addrconf.c

···
 	if (netif_carrier_ok(dev))
 		ndev->if_flags |= IF_READY;
 
-	/* protected by rtnl_lock */
-	rcu_assign_pointer(dev->ip6_ptr, ndev);
 
 	ipv6_mc_init_dev(ndev);
 	ndev->tstamp = jiffies;
···
 			      NULL);
 	addrconf_sysctl_register(ndev, &ndev->cnf);
 #endif
+	/* protected by rtnl_lock */
+	rcu_assign_pointer(dev->ip6_ptr, ndev);
 	return ndev;
 }