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 48099C4363A for ; Tue, 20 Oct 2020 17:19:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBA7022244 for ; Tue, 20 Oct 2020 17:19:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="PW80dGdC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730764AbgJTRTz (ORCPT ); Tue, 20 Oct 2020 13:19:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730473AbgJTRTz (ORCPT ); Tue, 20 Oct 2020 13:19:55 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D5D3C0613CE for ; Tue, 20 Oct 2020 10:19:55 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id ds1so1224508pjb.5 for ; Tue, 20 Oct 2020 10:19:55 -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:in-reply-to; bh=9kB87QIvnyTMqBYHcbE2q4kll5hngCNoz9GnopGzSUc=; b=PW80dGdCD6rre0mDtHqg0g644x/vnf7u1GdejAgmuz3ncimqOjSSDksic4TnwJi8v1 pFsW5PhKBmp8We/rMoWRzA0hi+soBzBuXBb/6XclxS5Xjq5ZMewDCe6XlqMDpM8ukGFA xeWNm6vMuO9UTT+elaRezsfh8+VQwfdK1QduQ= 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:in-reply-to; bh=9kB87QIvnyTMqBYHcbE2q4kll5hngCNoz9GnopGzSUc=; b=JsC63TLsmE1xhtqYVfy6QjXT1qLGKpQewRyWBz6H70O1TVbLzQ641Sl366NmInSPXW MRVgWCuGnnrwNEMs7fOl85T+ArY1W4k9DJlkaXaiZWkkzjkf54PtJiJWCJhoZR/AVp8j Dr52DeUn0WDjc05McVJAFofn72rYNOV4+WPOI+UjIxBA2JZULU04BEFY8L8odKwYQbYE nOv75gZmnr50MPv8dqkE3sixQ82pN61eIq7r1Uw/OmDMQI+JS60wUIniE8M2S6sA4HYw mTsfQ+BRqJwaKzCdK2fVug3x1TPjIomzWGpfG602xjSpg0/d8vDWINK5xsTtzhgG2ISf E3HQ== X-Gm-Message-State: AOAM530g7mmQ1ZVFKLbZG5kY/qnuJjaYWQmMXZeTr7GhX8Fe7AcAbSqE fj+VvK6WvVlwyeO8dxHVpU5cPe5j044PQA== X-Google-Smtp-Source: ABdhPJykSIPdEgQCaNSYfflPGq5tEWaRmRK4WWJ5Se7tU4VUSHCewM4qoRYoMQ4SlwuuSeQ/txHJ6A== X-Received: by 2002:a17:902:bf41:b029:d5:c01a:4f4f with SMTP id u1-20020a170902bf41b02900d5c01a4f4fmr982445pls.14.1603214394864; Tue, 20 Oct 2020 10:19:54 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id i7sm2721988pfo.208.2020.10.20.10.19.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2020 10:19:53 -0700 (PDT) Date: Tue, 20 Oct 2020 10:19:52 -0700 From: Kees Cook To: Jakub Kicinski Cc: laniel_francis@privacyrequired.com, 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: <202010201019.7BFEC3D@keescook> References: <20201016125216.10922-1-laniel_francis@privacyrequired.com> <20201019152331.20583-1-laniel_francis@privacyrequired.com> <20201019152331.20583-3-laniel_francis@privacyrequired.com> <20201019094355.4f6f3826@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202010191559.3AC2C3F97@keescook> <20201019163449.0a3f4675@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201019163449.0a3f4675@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Mon, Oct 19, 2020 at 04:34:49PM -0700, Jakub Kicinski wrote: > 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; > > ;) Oops, sorry, yes. ENOCOFFEE on my end. :) -- Kees Cook