From patchwork Sat Jan 11 09:51:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234008 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 2F377C33C9E for ; Sat, 11 Jan 2020 10:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 028AC214D8 for ; Sat, 11 Jan 2020 10:33:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578738801; bh=3s5JAX5Q2ODEjcC2HpUaI66ihhczXZpmWqli7dJibxU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=i5OksFQ1vkgc3YeDrJMKi7g6H8uVilKPaL04e96v4PMJH4YcR/BkNNEa75vEGHrU5 Yso6OzUdS/D1KkzH+XY3FNV43cjRic1wBc7YHCiNYqdKjMyrXEI8edflnjJY1QVFQm FX/j1y0aBK83yaGJuL/N07Tz+80xa1q0zE8wOHls= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731184AbgAKKdU (ORCPT ); Sat, 11 Jan 2020 05:33:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:47638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731514AbgAKKdS (ORCPT ); Sat, 11 Jan 2020 05:33:18 -0500 Received: from localhost (unknown [62.119.166.9]) (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 258A320842; Sat, 11 Jan 2020 10:33:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578738797; bh=3s5JAX5Q2ODEjcC2HpUaI66ihhczXZpmWqli7dJibxU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ATaFfo20IkngoTDMZUK5hCOVAQBwZf/0VXTcrJH9miBnIU2MUhs5XwQ8wZZXySMXx w9ae/4kQjc4AXOE4lOkEPCIeVzsQ5YONt/rCyqzxoQ0BM8rqnboBc/vuKjWGiUz/Ww xUO1n3fvQw4OShYchTBQzCI+aVnp0gqE6bBeZ+KY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wen Yang , Kevin Darbyshire-Bryant , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rg?= =?utf-8?q?ensen?= , "David S. Miller" , Cong Wang , cake@lists.bufferbloat.net, netdev@vger.kernel.org, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH 5.4 147/165] sch_cake: avoid possible divide by zero in cake_enqueue() Date: Sat, 11 Jan 2020 10:51:06 +0100 Message-Id: <20200111094939.776468385@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094921.347491861@linuxfoundation.org> References: <20200111094921.347491861@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wen Yang [ Upstream commit 68aab823c223646fab311f8a6581994facee66a0 ] The variables 'window_interval' is u64 and do_div() truncates it to 32 bits, which means it can test non-zero and be truncated to zero for division. The unit of window_interval is nanoseconds, so its lower 32-bit is relatively easy to exceed. Fix this issue by using div64_u64() instead. Fixes: 7298de9cd725 ("sch_cake: Add ingress mode") Signed-off-by: Wen Yang Cc: Kevin Darbyshire-Bryant Cc: Toke Høiland-Jørgensen Cc: David S. Miller Cc: Cong Wang Cc: cake@lists.bufferbloat.net Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_cake.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1769,7 +1769,7 @@ static s32 cake_enqueue(struct sk_buff * q->avg_window_begin)); u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC; - do_div(b, window_interval); + b = div64_u64(b, window_interval); q->avg_peak_bandwidth = cake_ewma(q->avg_peak_bandwidth, b, b > q->avg_peak_bandwidth ? 2 : 8);