1 files changed, 66 insertions, 16 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index e9403a26a1d5..1c2bf97ca168 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -84,7 +84,7 @@ struct raw_sock {
 	struct sock sk;
 	int bound;
 	int ifindex;
-	struct notifier_block notifier;
+	struct list_head notifier;
 	int loopback;
 	int recv_own_msgs;
 	int fd_frames;
@@ -96,6 +96,10 @@ struct raw_sock {
 	struct uniqframe __percpu *uniq;
 };
 
+static LIST_HEAD(raw_notifier_list);
+static DEFINE_SPINLOCK(raw_notifier_lock);
+static struct raw_sock *raw_busy_notifier;
+
 /*
  * Return pointer to store the extra msg flags for raw_recvmsg().
  * We use the space of one unsigned int beyond the 'struct sockaddr_can'
@@ -260,21 +264,16 @@ static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)
 	return err;
 }
 
-static int raw_notifier(struct notifier_block *nb,
-			unsigned long msg, void *ptr)
+static void raw_notify(struct raw_sock *ro, unsigned long msg,
+		       struct net_device *dev)
 {
-	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-	struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
 	struct sock *sk = &ro->sk;
 
 	if (!net_eq(dev_net(dev), &init_net))
-		return NOTIFY_DONE;
-
-	if (dev->type != ARPHRD_CAN)
-		return NOTIFY_DONE;
+		return;
 
 	if (ro->ifindex != dev->ifindex)
-		return NOTIFY_DONE;
+		return;
 
 	switch (msg) {
 
@@ -303,7 +302,28 @@ static int raw_notifier(struct notifier_block *nb,
 			sk->sk_error_report(sk);
 		break;
 	}
+}
+
+static int raw_notifier(struct notifier_block *nb, unsigned long msg,
+			void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+	if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+		return NOTIFY_DONE;
+	if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
+		return NOTIFY_DONE;
 
+	spin_lock(&raw_notifier_lock);
+	list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
+		spin_unlock(&raw_notifier_lock);
+		raw_notify(raw_busy_notifier, msg, dev);
+		spin_lock(&raw_notifier_lock);
+	}
+	raw_busy_notifier = NULL;
+	spin_unlock(&raw_notifier_lock);
 	return NOTIFY_DONE;
 }
 
@@ -332,9 +352,9 @@ static int raw_init(struct sock *sk)
 		return -ENOMEM;
 
 	/* set notifier */
-	ro->notifier.notifier_call = raw_notifier;
-
-	register_netdevice_notifier(&ro->notifier);
+	spin_lock(&raw_notifier_lock);
+	list_add_tail(&ro->notifier, &raw_notifier_list);
+	spin_unlock(&raw_notifier_lock);
 
 	return 0;
 }
@@ -349,7 +369,14 @@ static int raw_release(struct socket *sock)
 
 	ro = raw_sk(sk);
 
-	unregister_netdevice_notifier(&ro->notifier);
+	spin_lock(&raw_notifier_lock);
+	while (raw_busy_notifier == ro) {
+		spin_unlock(&raw_notifier_lock);
+		schedule_timeout_uninterruptible(1);
+		spin_lock(&raw_notifier_lock);
+	}
+	list_del(&ro->notifier);
+	spin_unlock(&raw_notifier_lock);
 
 	lock_sock(sk);
 
@@ -514,10 +541,18 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 				return -EFAULT;
 		}
 
+		rtnl_lock();
 		lock_sock(sk);
 
-		if (ro->bound && ro->ifindex)
+		if (ro->bound && ro->ifindex) {
 			dev = dev_get_by_index(&init_net, ro->ifindex);
+			if (!dev) {
+				if (count > 1)
+					kfree(filter);
+				err = -ENODEV;
+				goto out_fil;
+			}
+		}
 
 		if (ro->bound) {
 			/* (try to) register the new filters */
@@ -554,6 +589,7 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 			dev_put(dev);
 
 		release_sock(sk);
+		rtnl_unlock();
 
 		break;
 
@@ -566,10 +602,16 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 
 		err_mask &= CAN_ERR_MASK;
 
+		rtnl_lock();
 		lock_sock(sk);
 
-		if (ro->bound && ro->ifindex)
+		if (ro->bound && ro->ifindex) {
 			dev = dev_get_by_index(&init_net, ro->ifindex);
+			if (!dev) {
+				err = -ENODEV;
+				goto out_err;
+			}
+		}
 
 		/* remove current error mask */
 		if (ro->bound) {
@@ -591,6 +633,7 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 			dev_put(dev);
 
 		release_sock(sk);
+		rtnl_unlock();
 
 		break;
 
@@ -857,6 +900,10 @@ static const struct can_proto raw_can_proto = {
 	.prot       = &raw_proto,
 };
 
+static struct notifier_block canraw_notifier = {
+	.notifier_call = raw_notifier
+};
+
 static __init int raw_module_init(void)
 {
 	int err;
@@ -866,6 +913,8 @@ static __init int raw_module_init(void)
 	err = can_proto_register(&raw_can_proto);
 	if (err < 0)
 		printk(KERN_ERR "can: registration of raw protocol failed\n");
+	else
+		register_netdevice_notifier(&canraw_notifier);
 
 	return err;
 }
@@ -873,6 +922,7 @@ static __init int raw_module_init(void)
 static __exit void raw_module_exit(void)
 {
 	can_proto_unregister(&raw_can_proto);
+	unregister_netdevice_notifier(&canraw_notifier);
 }
 
 module_init(raw_module_init);