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=-6.9 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,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 D7F78CA90AF for ; Wed, 13 May 2020 09:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E3B6206B8 for ; Wed, 13 May 2020 09:59:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363990; bh=Oa+q0KIYYDTnW/Wjd+DAuMGDs+zRTcpchmQ85aZUICE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FXb1/sMWh2W39wjWzNfPocoi82B7zIRpEJ9t2DeH41/oYmjIqWvlbh7skH40VoX3n clicsR9HnhxCG6J3Q7H5CZlg6EmFPQhoqNHoXhOps+gm2GPcE9HtEuAyAnjVW98yQE ghDppODL2afzn/1VaERyvgCfRgsxBQfRhrZekXsY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387848AbgEMJww (ORCPT ); Wed, 13 May 2020 05:52:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:54352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387833AbgEMJwp (ORCPT ); Wed, 13 May 2020 05:52:45 -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 D9E29206D6; Wed, 13 May 2020 09:52:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363565; bh=Oa+q0KIYYDTnW/Wjd+DAuMGDs+zRTcpchmQ85aZUICE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bUwxdjBnUbDsqimmBu2zx6izP6Ydb1KR0DXcHl8E+5selFiX+lvpXP/GsLTRPWKT4 DwK+o4FKPakpQVAZsOwbmyQNlm7ZLl44IhJ3f9GaBMHc2Vm8UcvnpJNbVO5sgZwsK8 qGK4nFJS2ewlgjYgpwjoacIbOBwvZkh1RepV12Ps= 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 5.6 036/118] sch_sfq: validate silly quantum values Date: Wed, 13 May 2020 11:44:15 +0200 Message-Id: <20200513094420.600244790@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200513094417.618129545@linuxfoundation.org> References: <20200513094417.618129545@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 @@ -637,6 +637,15 @@ 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;