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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D53DECAAD5 for ; Mon, 29 Aug 2022 11:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229560AbiH2LMx (ORCPT ); Mon, 29 Aug 2022 07:12:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229683AbiH2LMO (ORCPT ); Mon, 29 Aug 2022 07:12:14 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FF9C5E335; Mon, 29 Aug 2022 04:08:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 09FB0B80EF5; Mon, 29 Aug 2022 11:05:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6DBD3C433D6; Mon, 29 Aug 2022 11:05:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661771144; bh=pOZExQVSyn7QCvb7/wjxQji+l6d/83WgeVnjV1UlHz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NzIAfc1lWyaufa685TbsO2Tl/qraD4Y9aU7NchqlD10K8SFpnmktxTi5JF7biZ280 /Bu/+k74MwQLBRbSJ+Adc1AthLQavE8mGscpyfFXvqadW7wF9P7AkxbqNupcf0blQH MOP9U80a5SjKKVmUjvMTljw8CQG6UtUbkYxrQdNs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 071/136] net: Fix data-races around weight_p and dev_weight_[rt]x_bias. Date: Mon, 29 Aug 2022 12:58:58 +0200 Message-Id: <20220829105807.557952194@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220829105804.609007228@linuxfoundation.org> References: <20220829105804.609007228@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit bf955b5ab8f6f7b0632cdef8e36b14e4f6e77829 ] While reading weight_p, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Also, dev_[rt]x_weight can be read/written at the same time. So, we need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to use the same weight_p while changing dev_[rt]x_weight, we add a mutex in proc_do_dev_weight(). Fixes: 3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/dev.c | 2 +- net/core/sysctl_net_core.c | 15 +++++++++------ net/sched/sch_generic.c | 2 +- 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 12b1811cb488b..1a0de071fcf45 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6437,7 +6437,7 @@ static int process_backlog(struct napi_struct *napi, int quota) net_rps_action_and_irq_enable(sd); } - napi->weight = dev_rx_weight; + napi->weight = READ_ONCE(dev_rx_weight); while (again) { struct sk_buff *skb; diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 5f88526ad61cc..ed20cbdd19315 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -236,14 +236,17 @@ static int set_default_qdisc(struct ctl_table *table, int write, static int proc_do_dev_weight(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { - int ret; + static DEFINE_MUTEX(dev_weight_mutex); + int ret, weight; + mutex_lock(&dev_weight_mutex); ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret != 0) - return ret; - - dev_rx_weight = weight_p * dev_weight_rx_bias; - dev_tx_weight = weight_p * dev_weight_tx_bias; + if (!ret && write) { + weight = READ_ONCE(weight_p); + WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias); + WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias); + } + mutex_unlock(&dev_weight_mutex); return ret; } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 30c29a9a2efd2..250d87d993cb7 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -409,7 +409,7 @@ static inline bool qdisc_restart(struct Qdisc *q, int *packets) void __qdisc_run(struct Qdisc *q) { - int quota = dev_tx_weight; + int quota = READ_ONCE(dev_tx_weight); int packets; while (qdisc_restart(q, &packets)) { -- 2.35.1