From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60C0FC43215 for ; Tue, 19 Nov 2019 06:11:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3385221852 for ; Tue, 19 Nov 2019 06:11:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574143914; bh=ot8YQMOjdWQCQ8H+b5ivcfntlpqgPW+01EAoQHUxv5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i2/R3SJdajZpWScLZV7COHD18Q0+vv4ra1VotFUnOFwm7Fmcmg2JpPU/R/II7U8X+ uDo6JcdDQ1YbFIqtv6UbVAOtJ2qtnuPM/77JgeXRkfmlgXtNoujbbmYvW1BaEKrrxV UxKjSn78VVPdGlGNkNhTp1uREcQtDkG0REwjgfz4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728036AbfKSFXm (ORCPT ); Tue, 19 Nov 2019 00:23:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:39352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727173AbfKSFXj (ORCPT ); Tue, 19 Nov 2019 00:23:39 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 114B82231A; Tue, 19 Nov 2019 05:23:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574141017; bh=ot8YQMOjdWQCQ8H+b5ivcfntlpqgPW+01EAoQHUxv5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bVeEtSYicoGshRnK2lnbwToBbbdAtgNGljNA1uulaLXheat6omvxhNK/7skAeP+dF XmZzt74CV9v/v0lT4EdN+vThHHds1yiH+Y5JD1LUkl4OzU8fxQ+6xEiMalenKTuX1R xZLy9PlTxBGLAc8ItI5POvdu1yv9QSF09pOJcKaI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ido Schimmel , Jiri Pirko , "David S. Miller" Subject: [PATCH 4.19 009/422] devlink: disallow reload operation during device cleanup Date: Tue, 19 Nov 2019 06:13:26 +0100 Message-Id: <20191119051400.803594450@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119051400.261610025@linuxfoundation.org> References: <20191119051400.261610025@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Pirko [ Upstream commit 5a508a254bed9a2e36a5fb96c9065532a6bf1e9c ] There is a race between driver code that does setup/cleanup of device and devlink reload operation that in some drivers works with the same code. Use after free could we easily obtained by running: while true; do echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/bind devlink dev reload pci/0000:00:10.0 & echo "0000:00:10.0" >/sys/bus/pci/drivers/mlxsw_spectrum2/unbind done Fix this by enabling reload only after setup of device is complete and disabling it at the beginning of the cleanup process. Reported-by: Ido Schimmel Fixes: 2d8dc5bbf4e7 ("devlink: Add support for reload") Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx4/main.c | 3 ++ drivers/net/ethernet/mellanox/mlxsw/core.c | 4 ++ drivers/net/netdevsim/netdev.c | 5 +++ include/net/devlink.h | 3 ++ net/core/devlink.c | 39 ++++++++++++++++++++++++++++- 5 files changed, 53 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/mellanox/mlx4/main.c +++ b/drivers/net/ethernet/mellanox/mlx4/main.c @@ -3982,6 +3982,7 @@ static int mlx4_init_one(struct pci_dev if (ret) goto err_params_unregister; + devlink_reload_enable(devlink); pci_save_state(pdev); return 0; @@ -4093,6 +4094,8 @@ static void mlx4_remove_one(struct pci_d struct devlink *devlink = priv_to_devlink(priv); int active_vfs = 0; + devlink_reload_disable(devlink); + if (mlx4_is_slave(dev)) persist->interface_state |= MLX4_INTERFACE_STATE_NOWAIT; --- a/drivers/net/ethernet/mellanox/mlxsw/core.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c @@ -1054,6 +1054,8 @@ int mlxsw_core_bus_device_register(const if (err) goto err_driver_init; } + if (!reload) + devlink_reload_enable(devlink); return 0; @@ -1088,6 +1090,8 @@ void mlxsw_core_bus_device_unregister(st { struct devlink *devlink = priv_to_devlink(mlxsw_core); + if (!reload) + devlink_reload_disable(devlink); if (mlxsw_core->reload_fail) { if (!reload) /* Only the parts that were not de-initialized in the --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "netdevsim.h" @@ -221,6 +222,8 @@ static int nsim_init(struct net_device * goto err_unreg_dev; nsim_ipsec_init(ns); + if (ns->devlink) + devlink_reload_enable(ns->devlink); return 0; @@ -243,6 +246,8 @@ static void nsim_uninit(struct net_devic { struct netdevsim *ns = netdev_priv(dev); + if (ns->devlink) + devlink_reload_disable(ns->devlink); nsim_ipsec_teardown(ns); nsim_devlink_teardown(ns); debugfs_remove_recursive(ns->ddir); --- a/include/net/devlink.h +++ b/include/net/devlink.h @@ -35,6 +35,7 @@ struct devlink { struct device *dev; possible_net_t _net; struct mutex lock; + u8 reload_enabled:1; char priv[0] __aligned(NETDEV_ALIGN); }; @@ -477,6 +478,8 @@ struct ib_device; struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size); int devlink_register(struct devlink *devlink, struct device *dev); void devlink_unregister(struct devlink *devlink); +void devlink_reload_enable(struct devlink *devlink); +void devlink_reload_disable(struct devlink *devlink); void devlink_free(struct devlink *devlink); int devlink_port_register(struct devlink *devlink, struct devlink_port *devlink_port, --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -2643,7 +2643,7 @@ static int devlink_nl_cmd_reload(struct struct devlink *devlink = info->user_ptr[0]; int err; - if (!devlink->ops->reload) + if (!devlink->ops->reload || !devlink->reload_enabled) return -EOPNOTSUPP; err = devlink_resources_validate(devlink, NULL, info); @@ -3889,6 +3889,8 @@ EXPORT_SYMBOL_GPL(devlink_register); void devlink_unregister(struct devlink *devlink) { mutex_lock(&devlink_mutex); + WARN_ON(devlink->ops->reload && + devlink->reload_enabled); devlink_notify(devlink, DEVLINK_CMD_DEL); list_del(&devlink->list); mutex_unlock(&devlink_mutex); @@ -3896,6 +3898,41 @@ void devlink_unregister(struct devlink * EXPORT_SYMBOL_GPL(devlink_unregister); /** + * devlink_reload_enable - Enable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at end of device initialization + * process when reload operation is supported. + */ +void devlink_reload_enable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + devlink->reload_enabled = true; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_enable); + +/** + * devlink_reload_disable - Disable reload of devlink instance + * + * @devlink: devlink + * + * Should be called at the beginning of device cleanup + * process when reload operation is supported. + */ +void devlink_reload_disable(struct devlink *devlink) +{ + mutex_lock(&devlink_mutex); + /* Mutex is taken which ensures that no reload operation is in + * progress while setting up forbidded flag. + */ + devlink->reload_enabled = false; + mutex_unlock(&devlink_mutex); +} +EXPORT_SYMBOL_GPL(devlink_reload_disable); + +/** * devlink_free - Free devlink instance resources * * @devlink: devlink