Revert "net: team: do not use dynamic lockdep key"

This reverts commit 39285e124e.

Looks like the change has unintended consequences in exposing
objects before they are initialized. Let's drop this patch
and try again in net-next.

Reported-by: syzbot+44ae022028805f4600fc@syzkaller.appspotmail.com
Fixes: 39285e124e ("net: team: do not use dynamic lockdep key")
Link: https://lore.kernel.org/all/20230907103124.6adb7256@kernel.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/team/team.c

@@ -1135,8 +1135,8 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
 			 struct netlink_ext_ack *extack)
 {
 	struct net_device *dev = team->dev;
-	char *portname = port_dev->name;
 	struct team_port *port;
+	char *portname = port_dev->name;
 	int err;
 
 	if (port_dev->flags & IFF_LOOPBACK) {
@@ -1203,26 +1203,6 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
 
 	memcpy(port->orig.dev_addr, port_dev->dev_addr, port_dev->addr_len);
 
-	err = dev_open(port_dev, extack);
-	if (err) {
-		netdev_dbg(dev, "Device %s opening failed\n",
-			   portname);
-		goto err_dev_open;
-	}
-
-	err = team_upper_dev_link(team, port, extack);
-	if (err) {
-		netdev_err(dev, "Device %s failed to set upper link\n",
-			   portname);
-		goto err_set_upper_link;
-	}
-
-	/* lockdep subclass variable(dev->nested_level) was updated by
-	 * team_upper_dev_link().
-	 */
-	team_unlock(team);
-	team_lock(team);
-
 	err = team_port_enter(team, port);
 	if (err) {
 		netdev_err(dev, "Device %s failed to enter team mode\n",
@@ -1230,6 +1210,13 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
 		goto err_port_enter;
 	}
 
+	err = dev_open(port_dev, extack);
+	if (err) {
+		netdev_dbg(dev, "Device %s opening failed\n",
+			   portname);
+		goto err_dev_open;
+	}
+
 	err = vlan_vids_add_by_dev(port_dev, dev);
 	if (err) {
 		netdev_err(dev, "Failed to add vlan ids to device %s\n",
@@ -1255,6 +1242,13 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
 		goto err_handler_register;
 	}
 
+	err = team_upper_dev_link(team, port, extack);
+	if (err) {
+		netdev_err(dev, "Device %s failed to set upper link\n",
+			   portname);
+		goto err_set_upper_link;
+	}
+
 	err = __team_option_inst_add_port(team, port);
 	if (err) {
 		netdev_err(dev, "Device %s failed to add per-port options\n",
@@ -1301,6 +1295,9 @@ err_set_slave_promisc:
 	__team_option_inst_del_port(team, port);
 
 err_option_port_add:
+	team_upper_dev_unlink(team, port);
+
+err_set_upper_link:
 	netdev_rx_handler_unregister(port_dev);
 
 err_handler_register:
@@ -1310,16 +1307,13 @@ err_enable_netpoll:
 	vlan_vids_del_by_dev(port_dev, dev);
 
 err_vids_add:
-	team_port_leave(team, port);
-
-err_port_enter:
-	team_upper_dev_unlink(team, port);
-
-err_set_upper_link:
 	dev_close(port_dev);
 
 err_dev_open:
+	team_port_leave(team, port);
 	team_port_set_orig_dev_addr(port);
+
+err_port_enter:
 	dev_set_mtu(port_dev, port->orig.mtu);
 
 err_set_mtu:
@@ -1622,7 +1616,6 @@ static int team_init(struct net_device *dev)
 	int err;
 
 	team->dev = dev;
-	mutex_init(&team->lock);
 	team_set_no_mode(team);
 	team->notifier_ctx = false;
 
@@ -1650,6 +1643,8 @@ static int team_init(struct net_device *dev)
 		goto err_options_register;
 	netif_carrier_off(dev);
 
+	lockdep_register_key(&team->team_lock_key);
+	__mutex_init(&team->lock, "team->team_lock_key", &team->team_lock_key);
 	netdev_lockdep_set_classes(dev);
 
 	return 0;
@@ -1670,7 +1665,7 @@ static void team_uninit(struct net_device *dev)
 	struct team_port *port;
 	struct team_port *tmp;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	list_for_each_entry_safe(port, tmp, &team->port_list, list)
 		team_port_del(team, port->dev);
 
@@ -1679,8 +1674,9 @@ static void team_uninit(struct net_device *dev)
 	team_mcast_rejoin_fini(team);
 	team_notify_peers_fini(team);
 	team_queue_override_fini(team);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 	netdev_change_features(dev);
+	lockdep_unregister_key(&team->team_lock_key);
 }
 
 static void team_destructor(struct net_device *dev)
@@ -1794,18 +1790,18 @@ static void team_set_rx_mode(struct net_device *dev)
 
 static int team_set_mac_address(struct net_device *dev, void *p)
 {
-	struct team *team = netdev_priv(dev);
 	struct sockaddr *addr = p;
+	struct team *team = netdev_priv(dev);
 	struct team_port *port;
 
 	if (dev->type == ARPHRD_ETHER && !is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
 	dev_addr_set(dev, addr->sa_data);
-	team_lock(team);
+	mutex_lock(&team->lock);
 	list_for_each_entry(port, &team->port_list, list)
 		if (team->ops.port_change_dev_addr)
 			team->ops.port_change_dev_addr(team, port);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 	return 0;
 }
 
@@ -1819,7 +1815,7 @@ static int team_change_mtu(struct net_device *dev, int new_mtu)
 	 * Alhough this is reader, it's guarded by team lock. It's not possible
 	 * to traverse list in reverse under rcu_read_lock
 	 */
-	team_lock(team);
+	mutex_lock(&team->lock);
 	team->port_mtu_change_allowed = true;
 	list_for_each_entry(port, &team->port_list, list) {
 		err = dev_set_mtu(port->dev, new_mtu);
@@ -1830,7 +1826,7 @@ static int team_change_mtu(struct net_device *dev, int new_mtu)
 		}
 	}
 	team->port_mtu_change_allowed = false;
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	dev->mtu = new_mtu;
 
@@ -1840,7 +1836,7 @@ unwind:
 	list_for_each_entry_continue_reverse(port, &team->port_list, list)
 		dev_set_mtu(port->dev, dev->mtu);
 	team->port_mtu_change_allowed = false;
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	return err;
 }
@@ -1894,20 +1890,20 @@ static int team_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)
 	 * Alhough this is reader, it's guarded by team lock. It's not possible
 	 * to traverse list in reverse under rcu_read_lock
 	 */
-	team_lock(team);
+	mutex_lock(&team->lock);
 	list_for_each_entry(port, &team->port_list, list) {
 		err = vlan_vid_add(port->dev, proto, vid);
 		if (err)
 			goto unwind;
 	}
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	return 0;
 
 unwind:
 	list_for_each_entry_continue_reverse(port, &team->port_list, list)
 		vlan_vid_del(port->dev, proto, vid);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	return err;
 }
@@ -1917,10 +1913,10 @@ static int team_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, u16 vid)
 	struct team *team = netdev_priv(dev);
 	struct team_port *port;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	list_for_each_entry(port, &team->port_list, list)
 		vlan_vid_del(port->dev, proto, vid);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	return 0;
 }
@@ -1942,9 +1938,9 @@ static void team_netpoll_cleanup(struct net_device *dev)
 {
 	struct team *team = netdev_priv(dev);
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	__team_netpoll_cleanup(team);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 }
 
 static int team_netpoll_setup(struct net_device *dev,
@@ -1954,7 +1950,7 @@ static int team_netpoll_setup(struct net_device *dev,
 	struct team_port *port;
 	int err = 0;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	list_for_each_entry(port, &team->port_list, list) {
 		err = __team_port_enable_netpoll(port);
 		if (err) {
@@ -1962,7 +1958,7 @@ static int team_netpoll_setup(struct net_device *dev,
 			break;
 		}
 	}
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 	return err;
 }
 #endif
@@ -1973,9 +1969,9 @@ static int team_add_slave(struct net_device *dev, struct net_device *port_dev,
 	struct team *team = netdev_priv(dev);
 	int err;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	err = team_port_add(team, port_dev, extack);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
 	if (!err)
 		netdev_change_features(dev);
@@ -1988,12 +1984,19 @@ static int team_del_slave(struct net_device *dev, struct net_device *port_dev)
 	struct team *team = netdev_priv(dev);
 	int err;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	err = team_port_del(team, port_dev);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 
-	if (!err)
+	if (err)
-		netdev_change_features(dev);
+		return err;
+
+	if (netif_is_team_master(port_dev)) {
+		lockdep_unregister_key(&team->team_lock_key);
+		lockdep_register_key(&team->team_lock_key);
+		lockdep_set_class(&team->lock, &team->team_lock_key);
+	}
+	netdev_change_features(dev);
 
 	return err;
 }
@@ -2313,13 +2316,13 @@ static struct team *team_nl_team_get(struct genl_info *info)
 	}
 
 	team = netdev_priv(dev);
-	__team_lock(team);
+	mutex_lock(&team->lock);
 	return team;
 }
 
 static void team_nl_team_put(struct team *team)
 {
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 	dev_put(team->dev);
 }
 
@@ -2981,9 +2984,9 @@ static void team_port_change_check(struct team_port *port, bool linkup)
 {
 	struct team *team = port->team;
 
-	team_lock(team);
+	mutex_lock(&team->lock);
 	__team_port_change_check(port, linkup);
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 }
 
 

drivers/net/team/team_mode_loadbalance.c

@@ -478,7 +478,7 @@ static void lb_stats_refresh(struct work_struct *work)
 	team = lb_priv_ex->team;
 	lb_priv = get_lb_priv(team);
 
-	if (!team_trylock(team)) {
+	if (!mutex_trylock(&team->lock)) {
 		schedule_delayed_work(&lb_priv_ex->stats.refresh_dw, 0);
 		return;
 	}
@@ -515,7 +515,7 @@ static void lb_stats_refresh(struct work_struct *work)
 	schedule_delayed_work(&lb_priv_ex->stats.refresh_dw,
 			      (lb_priv_ex->stats.refresh_interval * HZ) / 10);
 
-	team_unlock(team);
+	mutex_unlock(&team->lock);
 }
 
 static void lb_stats_refresh_interval_get(struct team *team,

include/linux/if_team.h

@@ -221,38 +221,10 @@ struct team {
 		atomic_t count_pending;
 		struct delayed_work dw;
 	} mcast_rejoin;
+	struct lock_class_key team_lock_key;
 	long mode_priv[TEAM_MODE_PRIV_LONGS];
 };
 
-static inline void __team_lock(struct team *team)
-{
-	mutex_lock(&team->lock);
-}
-
-static inline int team_trylock(struct team *team)
-{
-	return mutex_trylock(&team->lock);
-}
-
-#ifdef CONFIG_LOCKDEP
-static inline void team_lock(struct team *team)
-{
-	ASSERT_RTNL();
-	mutex_lock_nested(&team->lock, team->dev->nested_level);
-}
-
-#else
-static inline void team_lock(struct team *team)
-{
-	__team_lock(team);
-}
-#endif
-
-static inline void team_unlock(struct team *team)
-{
-	mutex_unlock(&team->lock);
-}
-
 static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
 				      struct sk_buff *skb)
 {