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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71474C77B75 for ; Fri, 5 May 2023 07:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231298AbjEEHgx (ORCPT ); Fri, 5 May 2023 03:36:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229810AbjEEHgv (ORCPT ); Fri, 5 May 2023 03:36:51 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 719D018158 for ; Fri, 5 May 2023 00:36:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683272163; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v1CDos4xXpfX0yUzIH2R6tkwubXHkIXYBoy2gEXH5JA=; b=Ulu1OIJv+F5PRIiVh/+oSWmT47A8tnohcll3b6MIOvPvGoXJ4oTI/pvuYX0hOoc6eyP/qV BoVNt4/dLOGV62nGPxxh/ilaxgUFqzdD5KUovqWrCiJZfK+Ps9hgk86kpDaAB2ySQ69Gr8 uMDP8vjVXwzRUrwJvwWe2jPii4PfuP4= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-281-6xL18v9TMvGD146HF3mZ6Q-1; Fri, 05 May 2023 03:36:02 -0400 X-MC-Unique: 6xL18v9TMvGD146HF3mZ6Q-1 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-3f1763fac8bso9413595e9.1 for ; Fri, 05 May 2023 00:36:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683272161; x=1685864161; h=content-transfer-encoding:in-reply-to:organization:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=v1CDos4xXpfX0yUzIH2R6tkwubXHkIXYBoy2gEXH5JA=; b=jXn8r4Pl9umf+b+6OP8qalzVXVyMInCyz3qaJ1uVAfOM3PsfWYiIVCwAne315K8I9W a42SkVZajUFsjV8Ttbul5E9UZx6e4xXFgBvh6bhpWO/F26bPSQNx314YrIR9UibLK3CV Vxnu4mwkRmjS6g5F5Vf2B2Jffwu9LNt+bPiI2NJnXB8y+qXmcMU6hqnTMQTBREndDXY0 2IIUqAa8Qb498EwPUtttUSYfaf9ARjgqSAonTRyT7os3Pl3wQfoGuFpqt0nbaNsMZlie oogYl3T0FBdUsyXlknwEPwFSIPBdgk1oLV0hgQepSxwL8fpEpel98H1Iq1XYjBaOJ6n2 oOAw== X-Gm-Message-State: AC+VfDz/5tj03EncxlBv68h7dwbxE/qKxyFfdyUoLIwtWcyCMA9APVQ2 N3uxHB4AoUsmVwJw6vhiBYhg2lInOvoVinF+l9+o68f+Z8mFF/SFTDjOQsaynoWgJiMJd4IQvyD 4y/P6XvJtVzXgBKd+MfnMmKvrBA== X-Received: by 2002:a1c:f60a:0:b0:3f2:5920:e198 with SMTP id w10-20020a1cf60a000000b003f25920e198mr327468wmc.34.1683272161233; Fri, 05 May 2023 00:36:01 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5XUDdNnSt2o2Ebxjr2vrScxpisR6Dhq9Ysweo7VXotuNFB3rkH+IP2VGzq0fyN3ub0us6E+w== X-Received: by 2002:a1c:f60a:0:b0:3f2:5920:e198 with SMTP id w10-20020a1cf60a000000b003f25920e198mr327446wmc.34.1683272160847; Fri, 05 May 2023 00:36:00 -0700 (PDT) Received: from ?IPV6:2003:cb:c71f:6900:2b25:fc69:599e:3986? (p200300cbc71f69002b25fc69599e3986.dip0.t-ipconnect.de. [2003:cb:c71f:6900:2b25:fc69:599e:3986]) by smtp.gmail.com with ESMTPSA id 16-20020a05600c021000b003f1940fe278sm7185780wmi.7.2023.05.05.00.35.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 05 May 2023 00:36:00 -0700 (PDT) Message-ID: Date: Fri, 5 May 2023 09:35:59 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH] sysctl: add config to make randomize_va_space RO To: Michael McCracken , linux-kernel@vger.kernel.org Cc: kernel-hardening@lists.openwall.com, serge@hallyn.com, tycho@tycho.pizza, Luis Chamberlain , Kees Cook , Iurii Zaikin , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org References: <20230504213002.56803-1-michael.mccracken@gmail.com> Content-Language: en-US From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230504213002.56803-1-michael.mccracken@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 04.05.23 23:30, Michael McCracken wrote: > Add config RO_RANDMAP_SYSCTL to set the mode of the randomize_va_space > sysctl to 0444 to disallow all runtime changes. This will prevent > accidental changing of this value by a root service. > > The config is disabled by default to avoid surprises. Can you elaborate why we care about "accidental changing of this value by a root service"? We cannot really stop root from doing a lot of stupid things (e.g., erase the root fs), so why do we particularly care here? -- Thanks, David / dhildenb