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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 94DB8C4338F for ; Thu, 12 Aug 2021 17:53:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AB9460C3F for ; Thu, 12 Aug 2021 17:53:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237135AbhHLRxt (ORCPT ); Thu, 12 Aug 2021 13:53:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:55116 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229851AbhHLRxs (ORCPT ); Thu, 12 Aug 2021 13:53:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 86C726023D; Thu, 12 Aug 2021 17:53:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628790802; bh=+DBNYMHW9C8tmDuzsVD2IYotEdpsRD+WdJebzOTS63s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jegYsXtcbMNzdIvbEX3MZpK2NVdUzHdJu+ngI7qnFJKyEpRaB/KrJiYn5rm390eRn 01SmHrk+QiH51VQDxIilpnkWJS8HDLDOadV4cBADDuGfMVc1daizdGdawOQmg6J8Vj yXHPlBLP4y+6FvTkBFUKWYUscaUsZ2j50K0dIeEP2sHpmR79NAIpYE9SbXsR/g8gd5 MluWNMM381PicRbSvkXOrwwDi+5WL0o5ztKSt7KYUtmvdLjneI0IIZhJQ8Pu0Ox2Ia AF5IRvRjJlnEzTkhv2w7jE/BvKXt4DnzBRUMI68oVV23nliy+VXfUAVk5ouJBE9qgA xc8JbWMD6FZ6Q== Date: Thu, 12 Aug 2021 10:53:21 -0700 From: Jakub Kicinski To: tcs.kernel@gmail.com, vinicius.gomes@intel.com Cc: jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net, netdev@vger.kernel.org, Haimin Zhang Subject: Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change Message-ID: <20210812105321.0de11e3e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <1628658609-1208-1-git-send-email-tcs_kernel@tencent.com> References: <1628658609-1208-1-git-send-email-tcs_kernel@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 11 Aug 2021 13:10:09 +0800 tcs.kernel@gmail.com wrote: > From: Haimin Zhang > > syzbot report an array-index-out-of-bounds in taprio_change > index 16 is out of range for type '__u16 [16]' > that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check > the return value of netdev_set_num_tc. > > Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com > Signed-off-by: Haimin Zhang > --- > net/sched/sch_taprio.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > index 9c79374..1ab2fc9 100644 > --- a/net/sched/sch_taprio.c > +++ b/net/sched/sch_taprio.c > @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, > taprio_set_picos_per_byte(dev, q); > > if (mqprio) { > - netdev_set_num_tc(dev, mqprio->num_tc); > + err = netdev_set_num_tc(dev, mqprio->num_tc); > + if (err) > + goto free_sched; taprio_set_picos_per_byte() already got called and applied some of the changes. It seems like the early return from taprio_parse_mqprio_opt() if dev->num_tc is non-zero is incorrect. That function is supposed to validate that mqprio_opt() is correct AFAIU. That would mean: Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule") Vinicius - WDYT? > for (i = 0; i < mqprio->num_tc; i++) > netdev_set_tc_queue(dev, i, > mqprio->count[i],