From: Ido Schimmel <idosch@mellanox.com>
Date: Fri, 21 Feb 2020 19:54:13 +0200
Subject: mlxsw: spectrum_router: Take router lock from inetaddr listeners
Patch-mainline: v5.7-rc1
Git-commit: 1be54763e156d5f1888ce272416806f77ae8b816
References: bsc#1176774

Another entry point into the routing code is from inetaddr listeners.
The driver registers listeners to IPv4 and IPv6 inetaddr notification
chains in order to understand when a RIF needs to be created or
destroyed.

Serialize access to shared router structures from these listeners by
taking the router lock when processing inetaddr events.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -7029,15 +7029,17 @@ static int mlxsw_sp_inetaddr_event(struc
 
 	/* NETDEV_UP event is handled by mlxsw_sp_inetaddr_valid_event */
 	if (event == NETDEV_UP)
-		goto out;
+		return NOTIFY_DONE;
 
 	router = container_of(nb, struct mlxsw_sp_router, inetaddr_nb);
+	mutex_lock(&router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(router->mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
 
 	err = __mlxsw_sp_inetaddr_event(router->mlxsw_sp, dev, event, NULL);
 out:
+	mutex_unlock(&router->lock);
 	return notifier_from_errno(err);
 }
 
@@ -7052,8 +7054,9 @@ int mlxsw_sp_inetaddr_valid_event(struct
 
 	mlxsw_sp = mlxsw_sp_lower_get(dev);
 	if (!mlxsw_sp)
-		goto out;
+		return NOTIFY_DONE;
 
+	mutex_lock(&mlxsw_sp->router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
@@ -7065,6 +7068,7 @@ int mlxsw_sp_inetaddr_valid_event(struct
 
 	err = __mlxsw_sp_inetaddr_event(mlxsw_sp, dev, event, ivi->extack);
 out:
+	mutex_unlock(&mlxsw_sp->router->lock);
 	return notifier_from_errno(err);
 }
 
@@ -7138,8 +7142,9 @@ int mlxsw_sp_inet6addr_valid_event(struc
 
 	mlxsw_sp = mlxsw_sp_lower_get(dev);
 	if (!mlxsw_sp)
-		goto out;
+		return NOTIFY_DONE;
 
+	mutex_lock(&mlxsw_sp->router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
@@ -7151,6 +7156,7 @@ int mlxsw_sp_inet6addr_valid_event(struc
 
 	err = __mlxsw_sp_inetaddr_event(mlxsw_sp, dev, event, i6vi->extack);
 out:
+	mutex_unlock(&mlxsw_sp->router->lock);
 	return notifier_from_errno(err);
 }