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=-7.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT 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 A4F18C04AB6 for ; Tue, 28 May 2019 07:10:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 504F5208C3 for ; Tue, 28 May 2019 07:10:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bgFwNm7+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727455AbfE1HK6 (ORCPT ); Tue, 28 May 2019 03:10:58 -0400 Received: from mail-lf1-f67.google.com ([209.85.167.67]:37469 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726986AbfE1HK4 (ORCPT ); Tue, 28 May 2019 03:10:56 -0400 Received: by mail-lf1-f67.google.com with SMTP id m15so13077460lfh.4 for ; Tue, 28 May 2019 00:10:55 -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:content-transfer-encoding:in-reply-to :user-agent; bh=ynfWVZAT+alkdWSrFWfQ62Goqe/tGGfT3VrMNKjpjqY=; b=bgFwNm7+1pgd6JqolEUxQRByPRGN1vZxI8M//me9z3DiO93l9obuCt9o9GNZt7fv/f KZZBISaE1EYLUBbY17g0G44R1JSWxKalm6wc/iT92mPbAEv9hMuuCp5+JCzzV/5o+jOo WkZsn4T3jrdXkz63dXltEv7Q4Xrou1+FWZ9r10qPAhZoDa2DAuoK/aR87PWRn9Fyqwui 2ZzSBuGhMxKw3KPHAmwlcMa2Oqfyd9H3ihUgFZl3m9kevk7eSgul1tteN4tQRoY5+NH3 eEIbMS1zZM2uJGm+YpVp17dXI3zMv2TpEwoSoMGwad74anaGMznDM7GyiZVXI/BxqMaG A8tg== 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:user-agent; bh=ynfWVZAT+alkdWSrFWfQ62Goqe/tGGfT3VrMNKjpjqY=; b=VaPJJIgTtdROtanXbID2myrBIFX1jk6Ht3k8niuroHAWvKQ0t44TUfqA0ZVY9hng8H DivszlwJm4cynjyLOC3DPmBCSSAltkQoVSfpB63vBqQesCX1Unkfe/vSCm3x7McJuIhl 1MOHXniK1seyaxwgW/HsTB0WE7888mcoxNmmLRCfrmv6YNMfZBz6BGhRCqYefUPOhaZa hwJJ1zYPoUP2NpbbRTaDKrN2ETY4w2Z95rBa//3XGKIiqzEYoTV6ksmYa9fE2TVn66F6 cMYOK8GubazhU0PhZ8tQIADf8CIGxrZ/TcU50DHvasVAIGzOD5G8HG/j4hOdoseVJbO5 4Ttw== X-Gm-Message-State: APjAAAXUjPFYxScBYJhAiuXDsau1NHXIfAzi0ssKEozxeIlLqC+WWdCI nFIZOQXQlIQAm0FVu253Nvk9TL1teqg= X-Google-Smtp-Source: APXvYqwIUjaetPcnQQPDn1Uq4N5rBWMVjAQhEJAxhYN9Tz/SMKkEI6VcqT0euSVA8ouuKKzM/LiPUQ== X-Received: by 2002:ac2:42c8:: with SMTP id n8mr14725619lfl.28.1559027454638; Tue, 28 May 2019 00:10:54 -0700 (PDT) Received: from uranus.localdomain ([5.18.103.226]) by smtp.gmail.com with ESMTPSA id z6sm2718712ljh.61.2019.05.28.00.10.53 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 28 May 2019 00:10:53 -0700 (PDT) Received: by uranus.localdomain (Postfix, from userid 1000) id 3D45946010A; Tue, 28 May 2019 10:10:53 +0300 (MSK) Date: Tue, 28 May 2019 10:10:53 +0300 From: Cyrill Gorcunov To: Dianzhang Chen Cc: LKML Subject: Re: [PATCH] kernel/sys.c: fix possible spectre-v1 in do_prlimit() Message-ID: <20190528071053.GL11013@uranus> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 28, 2019 at 10:37:10AM +0800, Dianzhang Chen wrote: > Hi, > Because when i reply your email，i always get 'Message rejected' from > gmail(get this rejection from all the recipients). I still don't know > how to deal with it, so i reply your email here: Hi! This is weird. Next time simply reply to LKML (I CC'ed it back). > Because of speculative execution, the attacker can bypass the bound > check `if (resource >= RLIM_NLIMITS)`. And then misprediction get detected and execution is dropped. So I still don't see a problem here, since we don't leak info even in such case. That said I don't mind for this patch but rather in a sake of code clarity, not because of spectre issue since it has nothing to do here. > as for array_index_nospec(index, size), it will clamp the index within > the range of [0, size), and attacker can't exploit speculative > execution to make the index out of range [0, size). > > > For more detail, please check the link below: > > https://github.com/torvalds/linux/commit/f3804203306e098dae9ca51540fcd5eb700d7f40