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 B467BC10F14 for ; Thu, 3 Oct 2019 16:01:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7AFAA222C4 for ; Thu, 3 Oct 2019 16:01:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118497; bh=AcEFQVZfnqefqvpMnJZjKPVSuzbiEQwQhCaY9hwlWMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YpE3WpeANVI21kKvmSHA9IG5Qym6RD3I/OR1oL7XdfmjmxyPmFGr2U/ZEe6bqsP+C RBU+YBUxxbtZC77Xs8D7eAmLuJAifZ0E5bLliVH+UCvCXW0DcZ024YMRsKpsiBIYlI haxIEqDoD9z1FjVAM76jft3ZRIt2cQn/6RCL3InY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729271AbfJCQBg (ORCPT ); Thu, 3 Oct 2019 12:01:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:45994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730888AbfJCQBg (ORCPT ); Thu, 3 Oct 2019 12:01:36 -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 8319B20700; Thu, 3 Oct 2019 16:01:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118495; bh=AcEFQVZfnqefqvpMnJZjKPVSuzbiEQwQhCaY9hwlWMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pBX9kVo/H/dRUrJqunxBJIpme5Uy86QUOP5BCA/p+n0YsoffrRy7cWlobKqKyzQEd hDF8lQ45mycJZiECZ8JvK6m+1yfQ4WsBm+D0Z95ESB3KbneNK9rYZ2517NvZ2JQg96 j+nMv96feNrzf6p/pU4YbWcppgZTihqmtWTenHeo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , Jakub Kicinski Subject: [PATCH 4.9 030/129] sch_netem: fix a divide by zero in tabledist() Date: Thu, 3 Oct 2019 17:52:33 +0200 Message-Id: <20191003154333.272336115@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154318.081116689@linuxfoundation.org> References: <20191003154318.081116689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit b41d936b5ecfdb3a4abc525ce6402a6c49cffddc ] syzbot managed to crash the kernel in tabledist() loading an empty distribution table. t = dist->table[rnd % dist->size]; Simply return an error when such load is attempted. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_netem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -711,7 +711,7 @@ static int get_dist_table(struct Qdisc * int i; size_t s; - if (n > NETEM_DIST_MAX) + if (!n || n > NETEM_DIST_MAX) return -EINVAL; s = sizeof(struct disttable) + n * sizeof(s16);