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,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 0FC32C433E0 for ; Mon, 18 May 2020 17:43:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2DE820872 for ; Mon, 18 May 2020 17:43:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823785; bh=NElWdHSPE0Co3MWskyrX7Zbj7D9KTvqkOaLCXT/v8lg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ydoto9weArmB7uNK/D/hz8VTzjV9wCMAsQBHDZzzM2QNzKQukhx9cGsp1ORRauy/Y oNykk4T9V+4M3xwW707eF62pbMkzPK3jPHh+8EocRhvahp7ZhQOWL/CCaB++tFg+lP /c7MV6/leb7RB7RcNKzGl8eDqA2/sA4T3JWGFFe8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728985AbgERRnE (ORCPT ); Mon, 18 May 2020 13:43:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:39950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728916AbgERRmt (ORCPT ); Mon, 18 May 2020 13:42:49 -0400 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 ECE3820715; Mon, 18 May 2020 17:42:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823768; bh=NElWdHSPE0Co3MWskyrX7Zbj7D9KTvqkOaLCXT/v8lg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DzBZCx1c4CH3S0x/lVvGWOqIVBNEKqJ7seSp6MncsPJm6xOohD2v4Z6yEk9vWgxX8 0jG+cxJ0dhczyUlGh056BawY4g7XDpitfRfxgBmMD5xipxNWAEuXLoF2OqijiPuZYT v+81IxN9EfEeHKRhsM6YbRkKD8rVH6aHVJE/J5ik= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot+0251e883fe39e7a0cb0a@syzkaller.appspotmail.com, "Jason A. Donenfeld" , "David S. Miller" Subject: [PATCH 4.9 08/90] sch_sfq: validate silly quantum values Date: Mon, 18 May 2020 19:35:46 +0200 Message-Id: <20200518173452.906332765@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173450.930655662@linuxfoundation.org> References: <20200518173450.930655662@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: Eric Dumazet [ Upstream commit df4953e4e997e273501339f607b77953772e3559 ] syzbot managed to set up sfq so that q->scaled_quantum was zero, triggering an infinite loop in sfq_dequeue() More generally, we must only accept quantum between 1 and 2^18 - 7, meaning scaled_quantum must be in [1, 0x7FFF] range. Otherwise, we also could have a loop in sfq_dequeue() if scaled_quantum happens to be 0x8000, since slot->allot could indefinitely switch between 0 and 0x8000. Fixes: eeaeb068f139 ("sch_sfq: allow big packets and be fair") Signed-off-by: Eric Dumazet Reported-by: syzbot+0251e883fe39e7a0cb0a@syzkaller.appspotmail.com Cc: Jason A. Donenfeld Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_sfq.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -635,6 +635,15 @@ static int sfq_change(struct Qdisc *sch, if (ctl->divisor && (!is_power_of_2(ctl->divisor) || ctl->divisor > 65536)) return -EINVAL; + + /* slot->allot is a short, make sure quantum is not too big. */ + if (ctl->quantum) { + unsigned int scaled = SFQ_ALLOT_SIZE(ctl->quantum); + + if (scaled <= 0 || scaled > SHRT_MAX) + return -EINVAL; + } + if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max, ctl_v1->Wlog)) return -EINVAL;