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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3B731C4363A for ; Tue, 20 Oct 2020 17:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C62A322242 for ; Tue, 20 Oct 2020 17:23:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="j31T+kYp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390876AbgJTRXL (ORCPT ); Tue, 20 Oct 2020 13:23:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390857AbgJTRXL (ORCPT ); Tue, 20 Oct 2020 13:23:11 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2972CC0613CE for ; Tue, 20 Oct 2020 10:23:11 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id t22so1363510plr.9 for ; Tue, 20 Oct 2020 10:23:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=C2whC7dxW7uUCx15c2+3j06uyxnCZ7apflsBs7iRZkw=; b=j31T+kYpVPSb8G7+0XJNMo3ngCFXQTxTlChxMq63AJIXv0q0hHe09F0bNrh80H46oG oac6zTN9cNnU+RQQOUrdKf832mCpEjILW/aEpL3FcOCM/VpcG1B0xVeQ4Gu+r3fkYg4R sbSAKB8Opy9iSHN7mvm6josCYSB+jz4ySPN04= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=C2whC7dxW7uUCx15c2+3j06uyxnCZ7apflsBs7iRZkw=; b=unB6Mexkid1jd8CwBCqmcdebvoeQKL8EgREZUN35qGw3Ji2rMVVk0rXtOk+8hpYKcv mfxqq8lhjfTXsK8B7Ott6cd2BIRW8NiukSd+ecf34HdxPfK4Fe+zheUkLEsudDWN5LDo KCWUCF7DKPrXAC1bBy/WzcsfsSdYNd6VDiFLwZOecva4srC8ll2pFlPWS+rkgmvVuy3o ZoDdrty7kEwea9zjWrNK9eK/3vi17w2bI5nKIeJbgwu26zxzrS8vnEiwwFzO4icJEZz2 LQAdRqAftUDYzoO96Jza7c+Nmxy2qQhAPDrO5hVoPCPbvMeqxGz7g3kbMFirE6eBoz7p iWMA== X-Gm-Message-State: AOAM531GxO8N1Z/0fZPOD7hcrdCVKgtTsvJVFP9KiTQiC7sPPWf4rmAf nXrnEV+PzOeUtstH3HzPclmcdwOcbOanaQ== X-Google-Smtp-Source: ABdhPJw+Xvk7WDG8BtEeO4/9z1QNsAOZ+PKIsVdsodrmAZ9VNkBpYUAm8VniEpyhhXr7+U+fyQrgjA== X-Received: by 2002:a17:90a:148:: with SMTP id z8mr3773544pje.173.1603214590685; Tue, 20 Oct 2020 10:23:10 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id m4sm2561498pgv.87.2020.10.20.10.23.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2020 10:23:09 -0700 (PDT) Date: Tue, 20 Oct 2020 10:23:09 -0700 From: Kees Cook To: Francis Laniel Cc: Jakub Kicinski , linux-hardening@vger.kernel.org, davem@davemloft.net Subject: Re: [RFC][PATCH v2 2/3] Modify return value of nla_strlcpy to match that of strscpy. Message-ID: <202010201022.B016A3A41A@keescook> References: <20201016125216.10922-1-laniel_francis@privacyrequired.com> <202010191559.3AC2C3F97@keescook> <20201019163449.0a3f4675@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <6912124.fRD6ipzQbq@machine> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6912124.fRD6ipzQbq@machine> Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Tue, Oct 20, 2020 at 12:28:49PM +0200, Francis Laniel wrote: > Le mardi 20 octobre 2020, 01:34:49 CEST Jakub Kicinski a écrit : > > On Mon, 19 Oct 2020 16:01:27 -0700 Kees Cook wrote: > > > On Mon, Oct 19, 2020 at 09:43:55AM -0700, Jakub Kicinski wrote: > > > > On Mon, 19 Oct 2020 17:23:30 +0200 laniel_francis@privacyrequired.com > > > > > > > > wrote: > > > > > -size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t > > > > > dstsize) > > > > > +ssize_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t > > > > > dstsize) > > > > > > > > > > { > > > > > > > > > > + size_t len; > > > > > + ssize_t ret; > > > > > > > > > > size_t srclen = nla_len(nla); > > > > > char *src = nla_data(nla); > > > > > > > > Sort local variables long to short. > > > > > > Specifically, "reverse christmas tree": > > > size_t srclen = nla_len(nla); > > > char *src = nla_data(nla); > > > size_t len; > > > ssize_t ret; > > > > Or even > > > > size_t srclen = nla_len(nla); > > char *src = nla_data(nla); > > ssize_t ret; > > size_t len; > > > > ;) > > I reordered the variables names for the v3. > Just to know, is it a new rule? Because scripts/checkpatch.pl did not report > anything and I was not aware of it. This is specific to netdev, but I actually can't find reference to this in either Documentation/process/coding-style.rst nor Documentation/networking/netdev-FAQ.rst. I swear I found this written down before, but it eludes me now. -- Kees Cook