From patchwork Mon Jan 11 13:01:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 360988 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 B418AC433E0 for ; Mon, 11 Jan 2021 13:46:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83F8522211 for ; Mon, 11 Jan 2021 13:46:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731382AbhAKNLY (ORCPT ); Mon, 11 Jan 2021 08:11:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:58548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731371AbhAKNLX (ORCPT ); Mon, 11 Jan 2021 08:11:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3CD35227C3; Mon, 11 Jan 2021 13:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370642; bh=z3O2d7uTqPV8mHw6kNG5G6BMybboTdu4NcYvXUMhMBM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YxMJkWHA6sE9dyoXes1TZd+Fa8BqocC2U0X/qdKu1+jNrYGg1LTU74lSRXE1UpzQm UlJf9LPEGBhJFsJjrAO7U79SwKMv1Ng6viyQDUNdUpmBFVyagF9KnU7jGTFcCn97j8 po/wULX1DJiQkH2lpWZ5gYbLejjF6yvWnBi2iFY0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Antoine Tenart , Alexander Duyck , Jakub Kicinski Subject: [PATCH 5.4 27/92] net-sysfs: take the rtnl lock when accessing xps_cpus_map and num_tc Date: Mon, 11 Jan 2021 14:01:31 +0100 Message-Id: <20210111130040.457884922@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130039.165470698@linuxfoundation.org> References: <20210111130039.165470698@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Antoine Tenart [ Upstream commit fb25038586d0064123e393cadf1fadd70a9df97a ] Accesses to dev->xps_cpus_map (when using dev->num_tc) should be protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't see an actual bug being triggered, but let's be safe here and take the rtnl lock while accessing the map in sysfs. Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes") Signed-off-by: Antoine Tenart Reviewed-by: Alexander Duyck Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/core/net-sysfs.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1235,8 +1235,8 @@ static const struct attribute_group dql_ static ssize_t xps_cpus_show(struct netdev_queue *queue, char *buf) { + int cpu, len, ret, num_tc = 1, tc = 0; struct net_device *dev = queue->dev; - int cpu, len, num_tc = 1, tc = 0; struct xps_dev_maps *dev_maps; cpumask_var_t mask; unsigned long index; @@ -1246,22 +1246,31 @@ static ssize_t xps_cpus_show(struct netd index = get_netdev_queue_index(queue); + if (!rtnl_trylock()) + return restart_syscall(); + if (dev->num_tc) { /* Do not allow XPS on subordinate device directly */ num_tc = dev->num_tc; - if (num_tc < 0) - return -EINVAL; + if (num_tc < 0) { + ret = -EINVAL; + goto err_rtnl_unlock; + } /* If queue belongs to subordinate dev use its map */ dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) - return -EINVAL; + if (tc < 0) { + ret = -EINVAL; + goto err_rtnl_unlock; + } } - if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) - return -ENOMEM; + if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) { + ret = -ENOMEM; + goto err_rtnl_unlock; + } rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_cpus_map); @@ -1284,9 +1293,15 @@ static ssize_t xps_cpus_show(struct netd } rcu_read_unlock(); + rtnl_unlock(); + len = snprintf(buf, PAGE_SIZE, "%*pb\n", cpumask_pr_args(mask)); free_cpumask_var(mask); return len < PAGE_SIZE ? len : -EINVAL; + +err_rtnl_unlock: + rtnl_unlock(); + return ret; } static ssize_t xps_cpus_store(struct netdev_queue *queue,