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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B977EC73C66 for ; Sun, 14 Jul 2019 09:52:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 792E42064A for ; Sun, 14 Jul 2019 09:52:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pfit/EM7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728247AbfGNJwD (ORCPT ); Sun, 14 Jul 2019 05:52:03 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:37883 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726799AbfGNJwC (ORCPT ); Sun, 14 Jul 2019 05:52:02 -0400 Received: by mail-wm1-f66.google.com with SMTP id f17so12398511wme.2 for ; Sun, 14 Jul 2019 02:52:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=/SqU2gFVMBbWyLJOkiidaC1t9EiWVorSKt8/qeakt/M=; b=pfit/EM7wrr88HzT2SnkIejcUSxurAVRXBuC529YfAeQ7jrFbenEqOe8z7XQmVFRSO aFiOoRF4zzIvHNkMaREz8eMn7g2NGBmMl28b2Aoqp2oPyurfuNwyltSNovk/JRiBMVim gmVRWXd2xypNmS4xQbc3sTm+l15sMiUlzZp6ayA46Vjgxa807fuSv33Ha7drReVJZvwT oLtHQsQepoxP0Rgh/8tQoimqcVXEC2hgomR3ipKj/ZV90PvceUONNBJdEMnBdM0MYm3n JknLDoKAatsEbdDQJRjvlFyM+rFPRkDF0SPOEIobHs04Q7jQsTtQlrHGJgIsjLthVY0t RM0w== 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:user-agent; bh=/SqU2gFVMBbWyLJOkiidaC1t9EiWVorSKt8/qeakt/M=; b=O0KKT9SKCSeTxUpZ9aw6YpDRI7NiPvzcAToI+FDnw6/Nby8xzEdYsvMji1PuOJMprC A5yuAx/R/sQ1C5ExQugmvMzNRfgczPoiwrvrgMFVVCawerUkWbPqsg5Aho1gjZ4ocxaB 3zR4brULHCzDoJMnaCf4hF7j1hMaEmjNn5W5XFkS86WX3zKjv76s5jhryTTXIV4Bedbz BfXegdCGdmI0zX3y3rcu3NhFLyrjxHDT9BT3zPWUunT+q+RqhnpYOLpQmoSeuD8IidkR YBwCdryRog/IdZOFdwMId2hywBayjLlRM3Q74XGrud3dhPNaRD9p6MYP73Bp9ITzcRmr CrrA== X-Gm-Message-State: APjAAAWV5+uSLyGHWrB3eETawwIc61siXCVTOUY7hGMvtlYHF276pZRR 1Diq4IYWrVZQ8xMUpEooY9Y3H4w= X-Google-Smtp-Source: APXvYqyg5kF3L2Tbl+LIpyWp0IPVfnjfDoxPe66saiIJxJrMWHWhtKi30Z89o6Z4jYvgxOv2uiAZFg== X-Received: by 2002:a7b:cbc6:: with SMTP id n6mr19402838wmi.14.1563097920485; Sun, 14 Jul 2019 02:52:00 -0700 (PDT) Received: from avx2 ([46.53.254.7]) by smtp.gmail.com with ESMTPSA id z6sm9606950wrw.2.2019.07.14.02.51.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Jul 2019 02:51:59 -0700 (PDT) Date: Sun, 14 Jul 2019 12:51:57 +0300 From: Alexey Dobriyan To: Linus Torvalds Cc: Andrew Morton , izbyshev@ispras.ru, Oleg Nesterov , Michal Kubecek , shasta@toxcorp.com, linux-kernel@vger.kernel.org, security@kernel.org Subject: Re: [PATCH] proc: revert /proc/*/cmdline rewrite Message-ID: <20190714095157.GA2276@avx2> References: <20190713072855.GB23167@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [re-add lists] On Sat, Jul 13, 2019 at 10:50:20AM -0700, Linus Torvalds wrote: > On Sat, Jul 13, 2019 at 12:29 AM Alexey Dobriyan wrote: > > > > /proc/*/cmdline continues to cause problems: > > If we're reverting this, then we should revert all the way back to the > original fixed-length one that had the original semantics and was > simple. No, because all those Java applications have command lines measured in dozens of kilobytes. > What was the problem with the one-line fix instead? The problem is that I can't even drag this trivia in out of _fear_ that it is userspace observable: https://marc.info/?t=155863429700002&r=1&w=4 [PATCH] elf: fix "start_code" evaluation and yet the patch which did a regression and an infoleak continues to be papered over and for which the only justification was "simplify and clarify".