ovs/gre, geneve: fix error path when creating an iface

BugLink: http://bugs.launchpad.net/bugs/1593235

After ipgre_newlink()/geneve_configure() call, the netdev is registered.

Fixes: 7e059158 ("vxlan, gre, geneve: Set a large MTU on ovs-created tunnel devices")
CC: David Wragg <david@weave.works>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 106da663)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <thadeu.cascardo@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/geneve.c

@@ -1442,6 +1442,7 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 {
 	struct nlattr *tb[IFLA_MAX + 1];
 	struct net_device *dev;
+	LIST_HEAD(list_kill);
 	int err;
 
 	memset(tb, 0, sizeof(tb));
@@ -1452,8 +1453,10 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 
 	err = geneve_configure(net, dev, &geneve_remote_unspec,
 			       0, 0, 0, htons(dst_port), true, 0);
-	if (err)
-		goto err;
+	if (err) {
+		free_netdev(dev);
+		return ERR_PTR(err);
+	}
 
 	/* openvswitch users expect packet sizes to be unrestricted,
 	 * so set the largest MTU we can.
@@ -1465,7 +1468,8 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 	return dev;
 
  err:
-	free_netdev(dev);
+	geneve_dellink(dev, &list_kill);
+	unregister_netdevice_many(&list_kill);
 	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(geneve_dev_create_fb);

net/ipv4/ip_gre.c

@@ -1230,6 +1230,7 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 {
 	struct nlattr *tb[IFLA_MAX + 1];
 	struct net_device *dev;
+	LIST_HEAD(list_kill);
 	struct ip_tunnel *t;
 	int err;
 
@@ -1245,8 +1246,10 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 	t->collect_md = true;
 
 	err = ipgre_newlink(net, dev, tb, NULL);
-	if (err < 0)
-		goto out;
+	if (err < 0) {
+		free_netdev(dev);
+		return ERR_PTR(err);
+	}
 
 	/* openvswitch users expect packet sizes to be unrestricted,
 	 * so set the largest MTU we can.
@@ -1257,7 +1260,8 @@ struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 
 	return dev;
 out:
-	free_netdev(dev);
+	ip_tunnel_dellink(dev, &list_kill);
+	unregister_netdevice_many(&list_kill);
 	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(gretap_fb_dev_create);