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 B95ADC352AA for ; Tue, 1 Oct 2019 16:44:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E2A62190F for ; Tue, 1 Oct 2019 16:44:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948266; bh=wBX0BLKAxEJ4pgZQUvtIbB9dURc/CT3Dk0SqiZRMAMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kr3+Jxr9YTglw07wEAGKDZg7lhX4PgY/BtbAURf4KaWKe5q4P582q3rCuQqDC666F okXbJDzLU8XZeVga+FN3RoYA4mG0z8/5FE3UqICuB1jKNffSoRzF025Kqyk0/iti2e NDjprFii1anwFy70+aBixg6XH6Zw0DMkxJL+o09Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387941AbfJAQoZ (ORCPT ); Tue, 1 Oct 2019 12:44:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:56598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387834AbfJAQoX (ORCPT ); Tue, 1 Oct 2019 12:44:23 -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 A47DB21855; Tue, 1 Oct 2019 16:44:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948262; bh=wBX0BLKAxEJ4pgZQUvtIbB9dURc/CT3Dk0SqiZRMAMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0fzcS7jzpy9Z5p1a1FhP95m+8et6J8/wXwuJ4qZFX9uX4sol0twFuVOnSLX5U6uZt 2aUsXsZtBQHQ+qtGVDjseuJPewoDLCx2ci0Tmw0zhhJ4ETGgMayqnOocFTcVKYP+mN WSbgVGKGGaN3wcQJ5k2olJvYOiVQkvq5d7lFJb7o= 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 4.19 43/43] sch_netem: fix a divide by zero in tabledist() Date: Tue, 1 Oct 2019 12:43:11 -0400 Message-Id: <20191001164311.15993-43-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164311.15993-1-sashal@kernel.org> References: <20191001164311.15993-1-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 4dfe10b9f96c8..86350fe5cfc8f 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -749,7 +749,7 @@ static int get_dist_table(struct Qdisc *sch, struct disttable **tbl, struct disttable *d; int i; - if (n > NETEM_DIST_MAX) + if (!n || n > NETEM_DIST_MAX) return -EINVAL; d = kvmalloc(sizeof(struct disttable) + n * sizeof(s16), GFP_KERNEL); -- 2.20.1