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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 27724ECDE46 for ; Wed, 24 Oct 2018 17:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE7F520824 for ; Wed, 24 Oct 2018 17:10:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE7F520824 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=davemloft.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727103AbeJYBjc (ORCPT ); Wed, 24 Oct 2018 21:39:32 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:38060 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726652AbeJYBjc (ORCPT ); Wed, 24 Oct 2018 21:39:32 -0400 Received: from localhost (c-67-183-62-245.hsd1.wa.comcast.net [67.183.62.245]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 49B58143A3225; Wed, 24 Oct 2018 10:10:40 -0700 (PDT) Date: Wed, 24 Oct 2018 10:10:28 -0700 (PDT) Message-Id: <20181024.101028.1211941922121897721.davem@davemloft.net> To: wanghaifine@gmail.com Cc: edumazet@google.com, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Change judgment len position From: David Miller In-Reply-To: <20181024154729.5312-1-wanghaifine@gmail.com> References: <20181024154729.5312-1-wanghaifine@gmail.com> X-Mailer: Mew version 6.7 on Emacs 26 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 24 Oct 2018 10:10:40 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wang Hai Date: Wed, 24 Oct 2018 23:47:29 +0800 > To determine whether len is less than zero, it should be put before > the function min_t, because the return value of min_t is not likely > to be less than zero. > > Signed-off-by: Wang Hai > --- > net/ipv4/tcp.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 10c624639..49af9fdc3 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -3301,11 +3301,11 @@ static int do_tcp_getsockopt(struct sock *sk, int level, > struct net *net = sock_net(sk); > int val, len; > > + len = min_t(unsigned int, len, sizeof(int)); > + > if (get_user(len, optlen)) > return -EFAULT; You can't be serious? 'len' has no value before the get_user() call.