4.18-stable review patch. If anyone has any objections, please let me know.
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From: Shalom Toledo shalomt@mellanox.com
[ Upstream commit a22712a962912faf257e857ab6857f56a93cfb34 ]
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 shalomt@mellanox.com Reviewed-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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlxsw/core.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c @@ -985,8 +985,8 @@ static int mlxsw_devlink_core_bus_device mlxsw_core->bus, mlxsw_core->bus_priv, true, devlink); - if (err) - mlxsw_core->reload_fail = true; + mlxsw_core->reload_fail = !!err; + return err; }
@@ -1126,8 +1126,15 @@ void mlxsw_core_bus_device_unregister(st const char *device_kind = mlxsw_core->bus_info->device_kind; 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); @@ -1140,9 +1147,12 @@ void mlxsw_core_bus_device_unregister(st 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); mlxsw_core_driver_put(device_kind); }