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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 22B49C35280 for ; Mon, 30 Sep 2019 20:41:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02A56224FE for ; Mon, 30 Sep 2019 20:41:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731456AbfI3UlF (ORCPT ); Mon, 30 Sep 2019 16:41:05 -0400 Received: from mga09.intel.com ([134.134.136.24]:60535 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730565AbfI3UlE (ORCPT ); Mon, 30 Sep 2019 16:41:04 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Sep 2019 10:18:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,568,1559545200"; d="scan'208";a="392149442" Received: from vcostago-desk1.jf.intel.com (HELO vcostago-desk1) ([10.54.70.82]) by fmsmga006.fm.intel.com with ESMTP; 30 Sep 2019 10:18:51 -0700 From: Vinicius Costa Gomes To: Vladimir Oltean , davem@davemloft.net Cc: jhs@mojatatu.com, xiyou.wangcong@gmail.com, netdev@vger.kernel.org, Vladimir Oltean Subject: Re: [PATCH v2 net] net: sched: taprio: Fix potential integer overflow in taprio_set_picos_per_byte In-Reply-To: <20190928230139.4027-1-olteanv@gmail.com> References: <20190928230139.4027-1-olteanv@gmail.com> Date: Mon, 30 Sep 2019 10:19:32 -0700 Message-ID: <87wodp7lcr.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Vladimir Oltean writes: > The speed divisor is used in a context expecting an s64, but it is > evaluated using 32-bit arithmetic. > > To avoid that happening, instead of multiplying by 1,000,000 in the > first place, simplify the fraction and do a standard 32 bit division > instead. > > Fixes: f04b514c0ce2 ("taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte") > Reported-by: Gustavo A. R. Silva > Suggested-by: Eric Dumazet > Signed-off-by: Vladimir Oltean > --- Acked-by: Vinicius Costa Gomes