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 second.openwall.net (second.openwall.net [193.110.157.125]) by smtp.lore.kernel.org (Postfix) with SMTP id 2997BC77B7C for ; Fri, 5 May 2023 07:36:28 +0000 (UTC) Received: (qmail 23816 invoked by uid 550); 5 May 2023 07:36:18 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 23790 invoked from network); 5 May 2023 07:36:18 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683272166; 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=cLu68bsMm2EkHeGubhHUCGYl5bPLnhh0O30Vnd4OWURFsbZ+i2mcAqHoS40EpgKQ93YyCo XJamv8ZV/1btxYzGpP0FHXRPmmqLoCQSCRXDRLnxOz4Rc4fy29dL8BSyb6RaZobwMgq8lf MdidvQ/7Wgv783xskSpHehuB4ZIxNo4= X-MC-Unique: FnHx9RA5OpaNWWBhD-v6gw-1 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=d2aj/C5vqpjVxmhC1ivrbPE2CW7Eg1Vbz5BiQj5vTShEcThHN7keQz2hIKxiyXwmdT 6H9Rd+j/okvGwjE3UKiDX0sa3zjJ4tt2B91lo18iHlRj+pYdrkqKJfZwiC8aSsDSkrLn wGUy0PHGCEKrGjwSYAZW957L62OtwjR3UXsIV/1fOUqijwN1vJBa+3uWQDFnvzruEn8j TIxwy0P5p7KrGQrCz7+oruKVI3SaCghX0swV3NiIGJMvDCUmMKRGHmD0ZgFHqof7IzWN 5AoF9c1w3KuvEc4bc7nAcG3lgduQQr+KzD7V7AQY4Utaf1v4AH6AZVXGVxNc1fm+8pwz 75xQ== X-Gm-Message-State: AC+VfDytI9gFYs2t1WriiGmFKZDjaP5wjHIEEJBeviZhwcaN8D1pLbRX ccA3eRbO5NerRB9PZyq4K/WD52QUqluy7DBx0hc+DFEWW/BI1TuNHipxhH0mgLzfqr2Zc1U28uG G0vvDmOngGxKyK+nn3TeotnYKvhga6+2nEA== X-Received: by 2002:a1c:f60a:0:b0:3f2:5920:e198 with SMTP id w10-20020a1cf60a000000b003f25920e198mr327461wmc.34.1683272161232; 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) 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> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230504213002.56803-1-michael.mccracken@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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