Lock correctly on device deletion

1 files changed, 11 insertions, 8 deletions

diff --git a/quicktun.c b/quicktun.c
index 3e2e628..44b7a7e 100644
--- a/quicktun.c
+++ b/quicktun.c
@@ -326,29 +326,32 @@ static int quicktun_cmd_delete_device(struct sk_buff *skb, struct genl_info *inf
 
 	name = nla_data(info->attrs[QUICKTUN_A_IFNAME]);
 
-	dev = dev_get_by_name(net, name);
-	if (!dev)
-		return -EINVAL;
+	rtnl_lock();
+
+	dev = __dev_get_by_name(net, name);
+	if (!dev) {
+		err = -EINVAL;
+		goto err_unlock;
+	}
 
 	if (dev->netdev_ops != &quicktun_ethernet_netdev_ops && dev->netdev_ops != &quicktun_ip_netdev_ops) {
 		err = -EINVAL;
-		goto err;
+		goto err_unlock;
 	}
 
 	tun = netdev_priv(dev);
 	sock = tun->sock;
 
-	rtnl_lock();
-	dev_put(dev);
 	unregister_netdevice(dev);
+
 	rtnl_unlock();
 
 	sock_release(sock);
 
 	return 0;
 
-err:
-	dev_put(dev);
+err_unlock:
+	rtnl_unlock();
 
 	return err;
 }