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=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 6889DC43461 for ; Thu, 10 Sep 2020 19:39:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35CBF21556 for ; Thu, 10 Sep 2020 19:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727894AbgIJTje (ORCPT ); Thu, 10 Sep 2020 15:39:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48202 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727997AbgIJTjO (ORCPT ); Thu, 10 Sep 2020 15:39:14 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB64DC061573; Thu, 10 Sep 2020 12:39:14 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 3D25712A30019; Thu, 10 Sep 2020 12:22:27 -0700 (PDT) Date: Thu, 10 Sep 2020 12:39:13 -0700 (PDT) Message-Id: <20200910.123913.1333297432408477303.davem@davemloft.net> To: linyunsheng@huawei.com Cc: jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, john.fastabend@gmail.com, eric.dumazet@gmail.com Subject: Re: [PATCH v2 net] net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc From: David Miller In-Reply-To: <1599562954-87257-1-git-send-email-linyunsheng@huawei.com> References: <1599562954-87257-1-git-send-email-linyunsheng@huawei.com> X-Mailer: Mew version 6.8 on Emacs 27.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [2620:137:e000::1:9]); Thu, 10 Sep 2020 12:22:27 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yunsheng Lin Date: Tue, 8 Sep 2020 19:02:34 +0800 > Currently there is concurrent reset and enqueue operation for the > same lockless qdisc when there is no lock to synchronize the > q->enqueue() in __dev_xmit_skb() with the qdisc reset operation in > qdisc_deactivate() called by dev_deactivate_queue(), which may cause > out-of-bounds access for priv->ring[] in hns3 driver if user has > requested a smaller queue num when __dev_xmit_skb() still enqueue a > skb with a larger queue_mapping after the corresponding qdisc is > reset, and call hns3_nic_net_xmit() with that skb later. > > Reused the existing synchronize_net() in dev_deactivate_many() to > make sure skb with larger queue_mapping enqueued to old qdisc(which > is saved in dev_queue->qdisc_sleeping) will always be reset when > dev_reset_queue() is called. > > Fixes: 6b3ba9146fe6 ("net: sched: allow qdiscs to handle locking") > Signed-off-by: Yunsheng Lin > --- > ChangeLog V2: > Reuse existing synchronize_net(). Applied and queued up for -stable, thank you.