Fixes for 5.10

[thirdparty/kernel/stable-queue.git] / releases / 4.14.60 / mlxsw-spectrum_switchdev-fix-port_vlan-refcounting.patch

From foo@baz Sat Jul 28 10:25:26 CEST 2018
From: Petr Machata <petrm@mellanox.com>
Date: Fri, 15 Jun 2018 16:23:38 +0300
Subject: mlxsw: spectrum_switchdev: Fix port_vlan refcounting

From: Petr Machata <petrm@mellanox.com>

[ Upstream commit 9e25826ffc942e985b8595b2f1cf2065d3880514 ]

Switchdev notifications for addition of SWITCHDEV_OBJ_ID_PORT_VLAN are
distributed not only on clean addition, but also when flags on an
existing VLAN are changed. mlxsw_sp_bridge_port_vlan_add() calls
mlxsw_sp_port_vlan_get() to get at the port_vlan in question, which
implicitly references the object. This then leads to discrepancies in
reference counting when the VLAN is removed. spectrum.c warns about the
problem when the module is removed:

[13578.493090] WARNING: CPU: 0 PID: 2454 at drivers/net/ethernet/mellanox/mlxsw/spectrum.c:2973 mlxsw_sp_port_remove+0xfd/0x110 [mlxsw_spectrum]
[...]
[13578.627106] Call Trace:
[13578.629617]  mlxsw_sp_fini+0x2a/0xe0 [mlxsw_spectrum]
[13578.634748]  mlxsw_core_bus_device_unregister+0x3e/0x130 [mlxsw_core]
[13578.641290]  mlxsw_pci_remove+0x13/0x40 [mlxsw_pci]
[13578.646238]  pci_device_remove+0x31/0xb0
[13578.650244]  device_release_driver_internal+0x14f/0x220
[13578.655562]  driver_detach+0x32/0x70
[13578.659183]  bus_remove_driver+0x47/0xa0
[13578.663134]  pci_unregister_driver+0x1e/0x80
[13578.667486]  mlxsw_sp_module_exit+0xc/0x3fa [mlxsw_spectrum]
[13578.673207]  __x64_sys_delete_module+0x13b/0x1e0
[13578.677888]  ? exit_to_usermode_loop+0x78/0x80
[13578.682374]  do_syscall_64+0x39/0xe0
[13578.685976]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix by putting the port_vlan when mlxsw_sp_port_vlan_bridge_join()
determines it's a flag-only change.

Fixes: b3529af6bb0d ("spectrum: Reference count VLAN entries")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -912,8 +912,10 @@ mlxsw_sp_port_vlan_bridge_join(struct ml
 	int err;
 
 	/* No need to continue if only VLAN flags were changed */
-	if (mlxsw_sp_port_vlan->bridge_port)
+	if (mlxsw_sp_port_vlan->bridge_port) {
+		mlxsw_sp_port_vlan_put(mlxsw_sp_port_vlan);
 		return 0;
+	}
 
 	err = mlxsw_sp_port_vlan_fid_join(mlxsw_sp_port_vlan, bridge_port);
 	if (err)