net/mlx5e: Move representor neigh cleanup to profile cleanup_tx

For IP tunnel encapsulation in ECMP (Equal-Cost Multipath) mode, as
the flow is duplicated to the peer eswitch, the related neighbour
information on the peer uplink representor is created as well.

In the cited commit, eswitch devcom unpair is moved to uplink unload
API, specifically the profile->cleanup_tx. If there is a encap rule
offloaded in ECMP mode, when one eswitch does unpair (because of
unloading the driver, for instance), and the peer rule from the peer
eswitch is going to be deleted, the use-after-free error is triggered
while accessing neigh info, as it is already cleaned up in uplink's
profile->disable, which is before its profile->cleanup_tx.

To fix this issue, move the neigh cleanup to profile's cleanup_tx
callback, and after mlx5e_cleanup_uplink_rep_tx is called. The neigh
init is moved to init_tx for symmeter.

[ 2453.376299] BUG: KASAN: slab-use-after-free in mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core]
[ 2453.379125] Read of size 4 at addr ffff888127af9008 by task modprobe/2496

[ 2453.381542] CPU: 7 PID: 2496 Comm: modprobe Tainted: G    B              6.4.0-rc7+ #15
[ 2453.383386] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 2453.384335] Call Trace:
[ 2453.384625]  <TASK>
[ 2453.384891]  dump_stack_lvl+0x33/0x50
[ 2453.385285]  print_report+0xc2/0x610
[ 2453.385667]  ? __virt_addr_valid+0xb1/0x130
[ 2453.386091]  ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core]
[ 2453.386757]  kasan_report+0xae/0xe0
[ 2453.387123]  ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core]
[ 2453.387798]  mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core]
[ 2453.388465]  mlx5e_rep_encap_entry_detach+0xa6/0xe0 [mlx5_core]
[ 2453.389111]  mlx5e_encap_dealloc+0xa7/0x100 [mlx5_core]
[ 2453.389706]  mlx5e_tc_tun_encap_dests_unset+0x61/0xb0 [mlx5_core]
[ 2453.390361]  mlx5_free_flow_attr_actions+0x11e/0x340 [mlx5_core]
[ 2453.391015]  ? complete_all+0x43/0xd0
[ 2453.391398]  ? free_flow_post_acts+0x38/0x120 [mlx5_core]
[ 2453.392004]  mlx5e_tc_del_fdb_flow+0x4ae/0x690 [mlx5_core]
[ 2453.392618]  mlx5e_tc_del_fdb_peers_flow+0x308/0x370 [mlx5_core]
[ 2453.393276]  mlx5e_tc_clean_fdb_peer_flows+0xf5/0x140 [mlx5_core]
[ 2453.393925]  mlx5_esw_offloads_unpair+0x86/0x540 [mlx5_core]
[ 2453.394546]  ? mlx5_esw_offloads_set_ns_peer.isra.0+0x180/0x180 [mlx5_core]
[ 2453.395268]  ? down_write+0xaa/0x100
[ 2453.395652]  mlx5_esw_offloads_devcom_event+0x203/0x530 [mlx5_core]
[ 2453.396317]  mlx5_devcom_send_event+0xbb/0x190 [mlx5_core]
[ 2453.396917]  mlx5_esw_offloads_devcom_cleanup+0xb0/0xd0 [mlx5_core]
[ 2453.397582]  mlx5e_tc_esw_cleanup+0x42/0x120 [mlx5_core]
[ 2453.398182]  mlx5e_rep_tc_cleanup+0x15/0x30 [mlx5_core]
[ 2453.398768]  mlx5e_cleanup_rep_tx+0x6c/0x80 [mlx5_core]
[ 2453.399367]  mlx5e_detach_netdev+0xee/0x120 [mlx5_core]
[ 2453.399957]  mlx5e_netdev_change_profile+0x84/0x170 [mlx5_core]
[ 2453.400598]  mlx5e_vport_rep_unload+0xe0/0xf0 [mlx5_core]
[ 2453.403781]  mlx5_eswitch_unregister_vport_reps+0x15e/0x190 [mlx5_core]
[ 2453.404479]  ? mlx5_eswitch_register_vport_reps+0x200/0x200 [mlx5_core]
[ 2453.405170]  ? up_write+0x39/0x60
[ 2453.405529]  ? kernfs_remove_by_name_ns+0xb7/0xe0
[ 2453.405985]  auxiliary_bus_remove+0x2e/0x40
[ 2453.406405]  device_release_driver_internal+0x243/0x2d0
[ 2453.406900]  ? kobject_put+0x42/0x2d0
[ 2453.407284]  bus_remove_device+0x128/0x1d0
[ 2453.407687]  device_del+0x240/0x550
[ 2453.408053]  ? waiting_for_supplier_show+0xe0/0xe0
[ 2453.408511]  ? kobject_put+0xfa/0x2d0
[ 2453.408889]  ? __kmem_cache_free+0x14d/0x280
[ 2453.409310]  mlx5_rescan_drivers_locked.part.0+0xcd/0x2b0 [mlx5_core]
[ 2453.409973]  mlx5_unregister_device+0x40/0x50 [mlx5_core]
[ 2453.410561]  mlx5_uninit_one+0x3d/0x110 [mlx5_core]
[ 2453.411111]  remove_one+0x89/0x130 [mlx5_core]
[ 2453.411628]  pci_device_remove+0x59/0xf0
[ 2453.412026]  device_release_driver_internal+0x243/0x2d0
[ 2453.412511]  ? parse_option_str+0x14/0x90
[ 2453.412915]  driver_detach+0x7b/0xf0
[ 2453.413289]  bus_remove_driver+0xb5/0x160
[ 2453.413685]  pci_unregister_driver+0x3f/0xf0
[ 2453.414104]  mlx5_cleanup+0xc/0x20 [mlx5_core]

Fixes: 2be5bd42 ("net/mlx5: Handle pairing of E-switch via uplink un/load APIs")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

@@ -1160,6 +1160,10 @@ static int mlx5e_init_rep_tx(struct mlx5e_priv *priv)
 		return err;
 	}
 
+	err = mlx5e_rep_neigh_init(rpriv);
+	if (err)
+		goto err_neigh_init;
+
 	if (rpriv->rep->vport == MLX5_VPORT_UPLINK) {
 		err = mlx5e_init_uplink_rep_tx(rpriv);
 		if (err)
@@ -1176,6 +1180,8 @@ static int mlx5e_init_rep_tx(struct mlx5e_priv *priv)
 	if (rpriv->rep->vport == MLX5_VPORT_UPLINK)
 		mlx5e_cleanup_uplink_rep_tx(rpriv);
 err_init_tx:
+	mlx5e_rep_neigh_cleanup(rpriv);
+err_neigh_init:
 	mlx5e_destroy_tises(priv);
 	return err;
 }
@@ -1189,22 +1195,17 @@ static void mlx5e_cleanup_rep_tx(struct mlx5e_priv *priv)
 	if (rpriv->rep->vport == MLX5_VPORT_UPLINK)
 		mlx5e_cleanup_uplink_rep_tx(rpriv);
 
+	mlx5e_rep_neigh_cleanup(rpriv);
 	mlx5e_destroy_tises(priv);
 }
 
 static void mlx5e_rep_enable(struct mlx5e_priv *priv)
 {
-	struct mlx5e_rep_priv *rpriv = priv->ppriv;
-
 	mlx5e_set_netdev_mtu_boundaries(priv);
-	mlx5e_rep_neigh_init(rpriv);
 }
 
 static void mlx5e_rep_disable(struct mlx5e_priv *priv)
 {
-	struct mlx5e_rep_priv *rpriv = priv->ppriv;
-
-	mlx5e_rep_neigh_cleanup(rpriv);
 }
 
 static int mlx5e_update_rep_rx(struct mlx5e_priv *priv)
@@ -1254,7 +1255,6 @@ static int uplink_rep_async_event(struct notifier_block *nb, unsigned long event
 
 static void mlx5e_uplink_rep_enable(struct mlx5e_priv *priv)
 {
-	struct mlx5e_rep_priv *rpriv = priv->ppriv;
 	struct net_device *netdev = priv->netdev;
 	struct mlx5_core_dev *mdev = priv->mdev;
 	u16 max_mtu;
@@ -1276,7 +1276,6 @@ static void mlx5e_uplink_rep_enable(struct mlx5e_priv *priv)
 	mlx5_notifier_register(mdev, &priv->events_nb);
 	mlx5e_dcbnl_initialize(priv);
 	mlx5e_dcbnl_init_app(priv);
-	mlx5e_rep_neigh_init(rpriv);
 	mlx5e_rep_bridge_init(priv);
 
 	netdev->wanted_features |= NETIF_F_HW_TC;
@@ -1291,7 +1290,6 @@ static void mlx5e_uplink_rep_enable(struct mlx5e_priv *priv)
 
 static void mlx5e_uplink_rep_disable(struct mlx5e_priv *priv)
 {
-	struct mlx5e_rep_priv *rpriv = priv->ppriv;
 	struct mlx5_core_dev *mdev = priv->mdev;
 
 	rtnl_lock();
@@ -1301,7 +1299,6 @@ static void mlx5e_uplink_rep_disable(struct mlx5e_priv *priv)
 	rtnl_unlock();
 
 	mlx5e_rep_bridge_cleanup(priv);
-	mlx5e_rep_neigh_cleanup(rpriv);
 	mlx5e_dcbnl_delete_app(priv);
 	mlx5_notifier_unregister(mdev, &priv->events_nb);
 	mlx5e_rep_tc_disable(priv);