From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:38794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727629AbeKCDpC (ORCPT ); Fri, 2 Nov 2018 23:45:02 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shalom Toledo , Jiri Pirko , Ido Schimmel , "David S. Miller" Subject: [PATCH 4.19 15/24] mlxsw: core: Fix devlink unregister flow Date: Fri, 2 Nov 2018 19:34:48 +0100 Message-Id: <20181102182842.146919357@linuxfoundation.org> In-Reply-To: <20181102182839.725385066@linuxfoundation.org> References: <20181102182839.725385066@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shalom Toledo [ 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 Reviewed-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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 @@ -943,8 +943,8 @@ 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; } @@ -1083,8 +1083,15 @@ void mlxsw_core_bus_device_unregister(st { 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(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); } EXPORT_SYMBOL(mlxsw_core_bus_device_unregister);