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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 72076ECE58A for ; Tue, 1 Oct 2019 16:47:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 404EC20659 for ; Tue, 1 Oct 2019 16:47:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948432; bh=uiHsB3meyPILAAZDTjLvMiCCFNR9pJuupii+/uI5/FA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mxJq52GE29HQyBp0GCrD3u13LN50mUKfZxMrFGUxT6Wj2RWTC3oF5eU0Br4Cj9aGl ayHjjxZqZfA0309D3kidU6oGY+wwqrkXDUPA82IRwTFaWagmHZq1LDG31aTR7ISSMo YhsZUe8TZDerfmJt/c+CNlpbyAlIwuwmaz0Cchus= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390325AbfJAQpd (ORCPT ); Tue, 1 Oct 2019 12:45:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:58066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390314AbfJAQpc (ORCPT ); Tue, 1 Oct 2019 12:45:32 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B1EA72190F; Tue, 1 Oct 2019 16:45:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948332; bh=uiHsB3meyPILAAZDTjLvMiCCFNR9pJuupii+/uI5/FA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CDzP/xyOYUJMPuoOUmg9ZRaO2Dw7K3TVjzTWi/NnV0Y0Se5PmHEHyTiV4WK7W9xF1 ybqkGjK8Oz5p/l+u7dzMTm5PAErKb7Xu0HK5wh08arbJ1GHC4FTtmUvVnbNkBQGKyW SDFNV6AUjfINaUqYaliZ5pZOsu/Kgupx6bA/csb4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , syzbot , Jakub Kicinski , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 19/19] sch_netem: fix a divide by zero in tabledist() Date: Tue, 1 Oct 2019 12:45:05 -0400 Message-Id: <20191001164505.16708-19-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164505.16708-1-sashal@kernel.org> References: <20191001164505.16708-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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: Sasha Levin --- net/sched/sch_netem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index e9812e21dbc9b..12e3ae09c4ba1 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -711,7 +711,7 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) 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); -- 2.20.1