From 25cc72a33835ed8a6f53180a822cadab855852ac Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Fri, 1 Sep 2017 10:52:31 +0200 Subject: mlxsw: spectrum: Forbid linking to devices that have uppers The mlxsw driver relies on NETDEV_CHANGEUPPER events to configure the device in case a port is enslaved to a master netdev such as bridge or bond. Since the driver ignores events unrelated to its ports and their uppers, it's possible to engineer situations in which the device's data path differs from the kernel's. One example to such a situation is when a port is enslaved to a bond that is already enslaved to a bridge. When the bond was enslaved the driver ignored the event - as the bond wasn't one of its uppers - and therefore a bridge port instance isn't created in the device. Until such configurations are supported forbid them by checking that the upper device doesn't have uppers of its own. Fixes: 0d65fc13042f ("mlxsw: spectrum: Implement LAG port join/leave") Signed-off-by: Ido Schimmel Reported-by: Nogah Frankel Tested-by: Nogah Frankel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 6 ++++++ include/linux/netdevice.h | 2 ++ net/core/dev.c | 3 ++- 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c index 60bf8f27cc00..c6a3e61b53bd 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c @@ -4139,6 +4139,8 @@ static int mlxsw_sp_netdevice_port_upper_event(struct net_device *lower_dev, return -EINVAL; if (!info->linking) break; + if (netdev_has_any_upper_dev(upper_dev)) + return -EINVAL; if (netif_is_lag_master(upper_dev) && !mlxsw_sp_master_lag_check(mlxsw_sp, upper_dev, info->upper_info)) @@ -4258,6 +4260,10 @@ static int mlxsw_sp_netdevice_port_vlan_event(struct net_device *vlan_dev, upper_dev = info->upper_dev; if (!netif_is_bridge_master(upper_dev)) return -EINVAL; + if (!info->linking) + break; + if (netdev_has_any_upper_dev(upper_dev)) + return -EINVAL; break; case NETDEV_CHANGEUPPER: upper_dev = info->upper_dev; diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 779b23595596..c99ba7914c0a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3866,6 +3866,8 @@ int netdev_walk_all_upper_dev_rcu(struct net_device *dev, bool netdev_has_upper_dev_all_rcu(struct net_device *dev, struct net_device *upper_dev); +bool netdev_has_any_upper_dev(struct net_device *dev); + void *netdev_lower_get_next_private(struct net_device *dev, struct list_head **iter); void *netdev_lower_get_next_private_rcu(struct net_device *dev, diff --git a/net/core/dev.c b/net/core/dev.c index 818dfa6e7ab5..86b4b0a79e7a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5668,12 +5668,13 @@ EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu); * Find out if a device is linked to an upper device and return true in case * it is. The caller must hold the RTNL lock. */ -static bool netdev_has_any_upper_dev(struct net_device *dev) +bool netdev_has_any_upper_dev(struct net_device *dev) { ASSERT_RTNL(); return !list_empty(&dev->adj_list.upper); } +EXPORT_SYMBOL(netdev_has_any_upper_dev); /** * netdev_master_upper_dev_get - Get master upper device -- cgit v1.2.3-55-g7522