Reference module as long as an interface exists

1 files changed, 18 insertions, 4 deletions

diff --git a/fastd.c b/fastd.c
index 55d2a25..505bba5 100644
--- a/fastd.c
+++ b/fastd.c
@@ -104,7 +104,7 @@ static int fastd_nl_event(struct notifier_block *nb,
 
 	list_for_each_entry_rcu(entry, &fastd_list, list) {
 		if (entry->owner == n->portid) {
-			ACCESS_ONCE(entry->owner) = 0;
+			entry->owner = 0;
 
 			queue_work(fastd_workqueue, &entry->destroy_work);
 		}
@@ -157,10 +157,15 @@ static const struct ethtool_ops fastd_ethtool_ops = {
 };
 
 
+static void fastd_netdev_free(struct net_device *dev) {
+	free_netdev(dev);
+	module_put(THIS_MODULE);
+}
+
 static void fastd_netdev_setup(struct net_device *dev)
 {
 	dev->ethtool_ops = &fastd_ethtool_ops;
-	dev->destructor = free_netdev;
+	dev->destructor = fastd_netdev_free;
 }
 
 static void fastd_netdev_init(struct net_device *dev)
@@ -225,10 +230,15 @@ static int fastd_cmd_create(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[FASTD_A_IFNAME])
 		name = nla_data(info->attrs[FASTD_A_IFNAME]);
 
+	if (!try_module_get(THIS_MODULE))
+		return -ENOENT;
+
 	dev = alloc_netdev(sizeof(struct fastd_struct), name,
 			   fastd_netdev_setup);
-	if (!dev)
-		return -ENOMEM;
+	if (!dev) {
+		err = -ENOMEM;
+		goto err_module_put;
+	}
 
 	dev_net_set(dev, net);
 
@@ -255,6 +265,10 @@ static int fastd_cmd_create(struct sk_buff *skb, struct genl_info *info)
 
 err_free_dev:
 	free_netdev(dev);
+
+err_module_put:
+	module_put(THIS_MODULE);
+
 	return err;
 }