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 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 312D4C388F9 for ; Fri, 23 Oct 2020 17:41:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBE4E2168B for ; Fri, 23 Oct 2020 17:41:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="MnFi588v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S461783AbgJWRl5 (ORCPT ); Fri, 23 Oct 2020 13:41:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S461716AbgJWRl5 (ORCPT ); Fri, 23 Oct 2020 13:41:57 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EE8CC0613CE for ; Fri, 23 Oct 2020 10:41:55 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id j18so1920853pfa.0 for ; Fri, 23 Oct 2020 10:41:55 -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=LXf+ps04hNA8w+H1+miMvzPAvHztSBOVbDdk9iOmq8k=; b=MnFi588vQfQJmITiUeRUTl7N1y3NTrdlvWnV+UsAmYTKoHTRgUZ3s0jjA/mkUTrzsw 4jBvh0zMjF1cYrjvYrjJbeTW8e6RtzRIFzoi6nIfhIvJAN1Cut8E0Xh/fVSBmFcIecJE d5IYeehTuGOCPdYKx4qrcIiIQaAthk1Q1km2k= 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=LXf+ps04hNA8w+H1+miMvzPAvHztSBOVbDdk9iOmq8k=; b=qNYEadSZUyseadNilJDrYqSdv1chv68zv/9JRbj5utLgUwdhc3ZN/twTt36fU5sUFz JV68tNHiZbMPUSS5ic+HTbpblpeSdDSgtiUSAXIryFAwNhPX82ghUgI1/ou/6Vf9sW3N N1waIiymd6Xgw2BXj3G+J+sMPW/dIp65UmTXtsa1q2+pwhweoIDx7gwoisx9NpXcClhe bFjF209HxFvGj9br0PR98q+ENva1XpE1v+3FA1TKRYUnqogVR3VmKTQhdwAl8ZjIvlIM 5+6M0NS4wsyl+xR7Q1wh4dVxoK6P27XbNkHsyLJg0B90rI/b1sIIpSqgVodHUISPCUyI BILw== X-Gm-Message-State: AOAM533eSACAXkx6hjGpPjy25c07Plz6aolWTQXmfBANQOg9sc+GrEw5 AkPtbr7V3lFDSm8LMRRldmo/Gw== X-Google-Smtp-Source: ABdhPJzNjzldV09CDkT31lkmu0Subn56dMJ8RuLmx5OlvCyYHBlYpnyIwPrAXMJJyGw5A+/mQH1xqw== X-Received: by 2002:aa7:83c9:0:b029:158:11ce:4672 with SMTP id j9-20020aa783c90000b029015811ce4672mr3221655pfn.23.1603474915101; Fri, 23 Oct 2020 10:41:55 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 197sm2787448pfa.170.2020.10.23.10.41.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 10:41:54 -0700 (PDT) Date: Fri, 23 Oct 2020 10:41:53 -0700 From: Kees Cook To: Jakub Kicinski Cc: David Laight , Francis Laniel , "linux-hardening@vger.kernel.org" , "netdev@vger.kernel.org" , "davem@davemloft.net" Subject: Re: [RFC][PATCH v3 3/3] Rename nla_strlcpy to nla_strscpy. Message-ID: <202010231041.9FAB4A2714@keescook> References: <20201020164707.30402-1-laniel_francis@privacyrequired.com> <20201020164707.30402-4-laniel_francis@privacyrequired.com> <202010211649.ABD53841B@keescook> <2286512.66XcFyAlgq@machine> <202010221302.5BA047AC9@keescook> <20201022160551.33d85912@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> <20201023082920.6addf3cb@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201023082920.6addf3cb@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Fri, Oct 23, 2020 at 08:29:20AM -0700, Jakub Kicinski wrote: > On Fri, 23 Oct 2020 08:07:44 +0000 David Laight wrote: > > FWIW I suspect the 'return -ERR on overflow' is going to bite us. > > Code that does p += strsxxx(p, ..., lim - p, ...) assuming (or not > > caring) about overflow goes badly wrong. > > I don't really care either way, but in netlink there's usually an > attribute per value, nothing combines strings like p += strx..(). > Looking at the conversion in patch 2 the callers just want to > check for overflow. Right -- this is a very narrow use-case (NLA). I think this series is fine as-is. -- Kees Cook