From a22712a962912faf257e857ab6857f56a93cfb34 Mon Sep 17 00:00:00 2001 From: Shalom Toledo Date: Mon, 29 Oct 2018 14:26:16 +0000 Subject: [PATCH] mlxsw: core: Fix devlink unregister flow After a failed reload, the driver is still registered to devlink, its devlink instance is still allocated and the 'reload_fail' flag is set. Then, in the next reload try, the driver's allocated devlink instance will be freed without unregistering from devlink and its components (e.g, resources). This scenario can cause a use-after-free if the user tries to execute command via devlink user-space tool. Fix by not freeing the devlink instance during reload (failed or not). Fixes: 24cc68ad6c46 ("mlxsw: core: Add support for reload") Signed-off-by: Shalom Toledo Reviewed-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/core.c | 24 +++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c index 937d0ace699a..30f751e69698 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/core.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c @@ -943,8 +943,8 @@ static int mlxsw_devlink_core_bus_device_reload(struct devlink *devlink, mlxsw_core->bus, mlxsw_core->bus_priv, true, devlink); - if (err) - mlxsw_core->reload_fail = true; + mlxsw_core->reload_fail = !!err; + return err; } @@ -1083,8 +1083,15 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core, { struct devlink *devlink = priv_to_devlink(mlxsw_core); - if (mlxsw_core->reload_fail) - goto reload_fail; + if (mlxsw_core->reload_fail) { + if (!reload) + /* Only the parts that were not de-initialized in the + * failed reload attempt need to be de-initialized. + */ + goto reload_fail_deinit; + else + return; + } if (mlxsw_core->driver->fini) mlxsw_core->driver->fini(mlxsw_core); @@ -1098,9 +1105,12 @@ void mlxsw_core_bus_device_unregister(struct mlxsw_core *mlxsw_core, if (!reload) devlink_resources_unregister(devlink, NULL); mlxsw_core->bus->fini(mlxsw_core->bus_priv); - if (reload) - return; -reload_fail: + + return; + +reload_fail_deinit: + devlink_unregister(devlink); + devlink_resources_unregister(devlink, NULL); devlink_free(devlink); } EXPORT_SYMBOL(mlxsw_core_bus_device_unregister); -- 2.30.2