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=-5.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7ACC1C4363A for ; Mon, 5 Oct 2020 08:22:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 287C52080A for ; Mon, 5 Oct 2020 08:22:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="NtxVFlQd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726005AbgJEIW5 (ORCPT ); Mon, 5 Oct 2020 04:22:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:59560 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725885AbgJEIWz (ORCPT ); Mon, 5 Oct 2020 04:22:55 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1601886174; 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: in-reply-to:in-reply-to:references:references; bh=aI/dA/YyB11Cz/SfAvKDlYSavn3LBvxcaaExPJKre2I=; b=NtxVFlQdoje0yt5u3Pybg9HVbK9tu7yz/O58LoQe+D1NJUg7pjyV8G8iYIauicgt1OESJH Fkquj1+MRZBlqS94+Yg1l5hDxCid2lp5C94+Lv4Z2x/q+ANS5/sD6yhwgH0YdIwJ8JBSbD /NVLL0AVEjQ3manT2FomzwcDHB7+kdc= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6E7C6AF99; Mon, 5 Oct 2020 08:22:54 +0000 (UTC) Date: Mon, 5 Oct 2020 10:22:52 +0200 From: Michal Hocko To: Topi Miettinen Cc: David Hildenbrand , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: optionally disable brk() Message-ID: <20201005082239.GQ4555@dhcp22.suse.cz> References: <20201002171921.3053-1-toiwoton@gmail.com> <653873ef-2a57-37e0-1ac3-fba763652b35@redhat.com> <2a0f5ade-d770-c36e-50bc-ff0c8e9dacbf@gmail.com> <20201005061248.GN4555@dhcp22.suse.cz> <7d7b1ac5-d6a7-5e43-8fb8-12b844d7f501@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d7b1ac5-d6a7-5e43-8fb8-12b844d7f501@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 05-10-20 11:11:35, Topi Miettinen wrote: [...] > I think hardened, security oriented systems should disable brk() completely > because it will increase the randomization of the process address space > (ASLR). This wouldn't be a good option to enable for systems where maximum > compatibility with legacy software is more important than any hardening. I believe we already do have means to filter syscalls from userspace for security hardened environements. Or is there any reason to duplicate that and control during the configuration time? -- Michal Hocko SUSE Labs