From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f69.google.com (mail-vk0-f69.google.com [209.85.213.69]) by kanga.kvack.org (Postfix) with ESMTP id E23AA6B0003 for ; Mon, 12 Feb 2018 18:27:21 -0500 (EST) Received: by mail-vk0-f69.google.com with SMTP id l205so10122620vke.13 for ; Mon, 12 Feb 2018 15:27:21 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id p44sor4194500uag.226.2018.02.12.15.27.20 for (Google Transport Security); Mon, 12 Feb 2018 15:27:20 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <17e5b515-84c8-dca2-1695-cdf819834ea2@huawei.com> References: <20180124175631.22925-1-igor.stoppa@huawei.com> <20180124175631.22925-5-igor.stoppa@huawei.com> <20180126053542.GA30189@bombadil.infradead.org> <8818bfd4-dd9f-f279-0432-69b59531bd41@huawei.com> <17e5b515-84c8-dca2-1695-cdf819834ea2@huawei.com> From: Kees Cook Date: Mon, 12 Feb 2018 15:27:19 -0800 Message-ID: Subject: Re: [kernel-hardening] [PATCH 4/6] Protectable Memory Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Igor Stoppa Cc: Boris Lukashev , Christopher Lameter , Matthew Wilcox , Jann Horn , Jerome Glisse , Michal Hocko , Laura Abbott , Christoph Hellwig , linux-security-module , Linux-MM , kernel list , Kernel Hardening On Sun, Feb 4, 2018 at 7:05 AM, Igor Stoppa wrote: > On 04/02/18 00:29, Boris Lukashev wrote: >> On Sat, Feb 3, 2018 at 3:32 PM, Igor Stoppa wrote: > > [...] > >>> What you are suggesting, if I have understood it correctly, is that, >>> when the pool is protected, the addresses already given out, will become >>> traps that get resolved through a lookup table that is built based on >>> the content of each allocation. >>> >>> That seems to generate a lot of overhead, not to mention the fact that >>> it might not play very well with the MMU. >> >> That is effectively what i'm suggesting - as a form of protection for >> consumers against direct reads of data which may have been corrupted >> by some irrelevant means. In the context of pmalloc, it would probably >> be a separate type of ro+verified pool > ok, that seems more like an extension though. > > ATM I am having problems gaining traction to get even the basic merged :-) > > I would consider this as a possibility for future work, unless it is > said that it's necessary for pmalloc to be accepted ... I would agree: let's get basic functionality in first. Both verification and the physmap part can be done separately, IMO. -Kees -- Kees Cook Pixel Security -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org