Merge branch 'can-fixes-for-6-5-rc7'

Oliver Hartkopp says:

====================
CAN fixes for 6.5-rc7

The isotp fix removes an unnecessary check which leads to delays and/or
a wrong error notification.

The fix for the CAN_RAW socket solves the last issue that has been
introduced with commit ee8b94c ("can: raw: fix receiver memory leak")
in this upstream cycle (detected by Eric Dumazet).
====================

Link: https://lore.kernel.org/r/20230821144547.6658-1-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

net/can/isotp.c

@@ -188,12 +188,6 @@ static bool isotp_register_rxid(struct isotp_sock *so)
 	return (isotp_bc_flags(so) == 0);
 }
 
-static bool isotp_register_txecho(struct isotp_sock *so)
-{
-	/* all modes but SF_BROADCAST register for tx echo skbs */
-	return (isotp_bc_flags(so) != CAN_ISOTP_SF_BROADCAST);
-}
-
 static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
 {
 	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
@@ -1209,7 +1203,7 @@ static int isotp_release(struct socket *sock)
 	lock_sock(sk);
 
 	/* remove current filters & unregister */
-	if (so->bound && isotp_register_txecho(so)) {
+	if (so->bound) {
 		if (so->ifindex) {
 			struct net_device *dev;
 
@@ -1332,14 +1326,12 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 		can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
 				isotp_rcv, sk, "isotp", sk);
 
-	if (isotp_register_txecho(so)) {
-		/* no consecutive frame echo skb in flight */
-		so->cfecho = 0;
+	/* no consecutive frame echo skb in flight */
+	so->cfecho = 0;
 
-		/* register for echo skb's */
-		can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
-				isotp_rcv_echo, sk, "isotpe", sk);
-	}
+	/* register for echo skb's */
+	can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
+			isotp_rcv_echo, sk, "isotpe", sk);
 
 	dev_put(dev);
 
@@ -1560,7 +1552,7 @@ static void isotp_notify(struct isotp_sock *so, unsigned long msg,
 	case NETDEV_UNREGISTER:
 		lock_sock(sk);
 		/* remove current filters & unregister */
-		if (so->bound && isotp_register_txecho(so)) {
+		if (so->bound) {
 			if (isotp_register_rxid(so))
 				can_rx_unregister(dev_net(dev), dev, so->rxid,
 						  SINGLE_MASK(so->rxid),

net/can/raw.c

@@ -85,6 +85,7 @@ struct raw_sock {
 	int bound;
 	int ifindex;
 	struct net_device *dev;
+	netdevice_tracker dev_tracker;
 	struct list_head notifier;
 	int loopback;
 	int recv_own_msgs;
@@ -285,8 +286,10 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg,
 	case NETDEV_UNREGISTER:
 		lock_sock(sk);
 		/* remove current filters & unregister */
-		if (ro->bound)
+		if (ro->bound) {
 			raw_disable_allfilters(dev_net(dev), dev, sk);
+			netdev_put(dev, &ro->dev_tracker);
+		}
 
 		if (ro->count > 1)
 			kfree(ro->filter);
@@ -391,10 +394,12 @@ static int raw_release(struct socket *sock)
 
 	/* remove current filters & unregister */
 	if (ro->bound) {
-		if (ro->dev)
+		if (ro->dev) {
 			raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
-		else
+			netdev_put(ro->dev, &ro->dev_tracker);
+		} else {
 			raw_disable_allfilters(sock_net(sk), NULL, sk);
+		}
 	}
 
 	if (ro->count > 1)
@@ -445,18 +450,20 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 			goto out;
 		}
 		if (dev->type != ARPHRD_CAN) {
-			dev_put(dev);
 			err = -ENODEV;
-			goto out;
+			goto out_put_dev;
 		}
+
 		if (!(dev->flags & IFF_UP))
 			notify_enetdown = 1;
 
 		ifindex = dev->ifindex;
 
 		/* filters set by default/setsockopt */
 		err = raw_enable_allfilters(sock_net(sk), dev, sk);
-		dev_put(dev);
+		if (err)
+			goto out_put_dev;
+
 	} else {
 		ifindex = 0;
 
@@ -467,18 +474,28 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	if (!err) {
 		if (ro->bound) {
 			/* unregister old filters */
-			if (ro->dev)
+			if (ro->dev) {
 				raw_disable_allfilters(dev_net(ro->dev),
 						       ro->dev, sk);
-			else
+				/* drop reference to old ro->dev */
+				netdev_put(ro->dev, &ro->dev_tracker);
+			} else {
 				raw_disable_allfilters(sock_net(sk), NULL, sk);
+			}
 		}
 		ro->ifindex = ifindex;
 		ro->bound = 1;
+		/* bind() ok -> hold a reference for new ro->dev */
 		ro->dev = dev;
+		if (ro->dev)
+			netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL);
 	}
 
- out:
+out_put_dev:
+	/* remove potential reference from dev_get_by_index() */
+	if (dev)
+		dev_put(dev);
+out:
 	release_sock(sk);
 	rtnl_unlock();