4.17-stable review patch. If anyone has any objections, please let me know.
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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 @@ -1013,8 +1013,10 @@ 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)