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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2C8D5C3F2D1 for ; Thu, 5 Mar 2020 20:49:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03C382072D for ; Thu, 5 Mar 2020 20:49:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=tycho-ws.20150623.gappssmtp.com header.i=@tycho-ws.20150623.gappssmtp.com header.b="oCjzxHqs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726162AbgCEUt1 (ORCPT ); Thu, 5 Mar 2020 15:49:27 -0500 Received: from mail-yw1-f67.google.com ([209.85.161.67]:45992 "EHLO mail-yw1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbgCEUt1 (ORCPT ); Thu, 5 Mar 2020 15:49:27 -0500 Received: by mail-yw1-f67.google.com with SMTP id d206so34698ywa.12 for ; Thu, 05 Mar 2020 12:49:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tycho-ws.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=5zmgxN7VRZXC7kbix0t7HZalzUvTentTfjnGm/3hMTE=; b=oCjzxHqsExisvhlxj2vLbWI+LleP320DIA63HiMC3CvCVE+taSKApySOErK4ZOUpEt J9NEAZwHZEmWGlvwUQRcTkTuMMzGpWOQXnz4PiGwEe5CWdNMxavPFDWW2EAGixCQhviZ +I4OFEjaLBOeE10vj1L+uU8FohllLaMLab6RAz0XnnMv15zFailN4BfRGHiOaoAiaIYw 8y7qzIaNpPZH88IK1Cp3LTrqck3d8e8y5MxZg3BI38HsHzkuz/kBeEblxNYQ8e5miY8W LR739rAjjIcqXS5O5Y8bv+USeISElSCSY4fbxmQTRCK7NaVpZZ18/K2gcxXqCO097Yi6 pKWw== 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=5zmgxN7VRZXC7kbix0t7HZalzUvTentTfjnGm/3hMTE=; b=dRwHRcN3IRrpoZP9QvaxtA7LyXF04ml8+HocI3NDNoRB2a+jE3s7tAzMiFDRDlUW5l u22wIjs89UolcRxtxIfYZ4qvlVpQ5XpC8gZYm+TsifDEYDAXFEFBJNC528b/Sff8hD0R tXmRJBCgx0hJM/9tUiu7wNmSxhcp7PDjvErP+QbPN2tPOc7YT0l1IYLGHhsAp8Ff6kRX 7BY2KrELVl5IdCg3irwtOUpW1LHQY3HQcXH2KkPdutCnHekm9BxbFrQWt4RUHXVRmxVh tGdvhcD4t18BDCEfAAohaeRPXWryRp5RTXJgL5F8ExZpnEGS0OnlOK8XjGBkFAxywZBq YuIA== X-Gm-Message-State: ANhLgQ3EwiW4Uzo1Y/9+ulIn9pX074Q/401gV1N68VUi2rKScY9ysys8 SWxEEgEtlMSVoj/SNH6aw4qZUg== X-Google-Smtp-Source: ADFU+vut5SaFR53pXBOtJjgao2EQ5xqKFPyU2dbqIJP6N0WO2apubN/ljUNmlK9XJyrF+68bzRL6FA== X-Received: by 2002:a25:860d:: with SMTP id y13mr137357ybk.310.1583441366443; Thu, 05 Mar 2020 12:49:26 -0800 (PST) Received: from cisco ([2607:fb90:17d4:133:1002:9a44:e2a2:4464]) by smtp.gmail.com with ESMTPSA id s63sm12469943ywd.82.2020.03.05.12.49.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Mar 2020 12:49:25 -0800 (PST) Date: Thu, 5 Mar 2020 13:49:08 -0700 From: Tycho Andersen To: Arvind Sankar Cc: Kees Cook , "Tobin C . Harding" , kernel-hardening@lists.openwall.com, Dave Hansen , Andy Lutomirski , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] x86/mm/init_32: Stop printing the virtual memory layout Message-ID: <20200305204908.GA6506@cisco> References: <202003021039.257258E1B@keescook> <20200305150152.831697-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200305150152.831697-1-nivedita@alum.mit.edu> 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 On Thu, Mar 05, 2020 at 10:01:52AM -0500, Arvind Sankar wrote: > For security, don't display the kernel's virtual memory layout. > > Kees Cook points out: > "These have been entirely removed on other architectures, so let's > just do the same for ia32 and remove it unconditionally." > > 071929dbdd86 ("arm64: Stop printing the virtual memory layout") > 1c31d4e96b8c ("ARM: 8820/1: mm: Stop printing the virtual memory layout") > 31833332f798 ("m68k/mm: Stop printing the virtual memory layout") > fd8d0ca25631 ("parisc: Hide virtual kernel memory layout") > adb1fe9ae2ee ("mm/page_alloc: Remove kernel address exposure in free_reserved_area()") > > Signed-off-by: Arvind Sankar Acked-by: Tycho Andersen