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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 97E76C32789 for ; Tue, 6 Nov 2018 21:05:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52B162083D for ; Tue, 6 Nov 2018 21:05:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52B162083D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730864AbeKGGcJ (ORCPT ); Wed, 7 Nov 2018 01:32:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52292 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726671AbeKGGcJ (ORCPT ); Wed, 7 Nov 2018 01:32:09 -0500 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id DEC5A94B; Tue, 6 Nov 2018 21:05:00 +0000 (UTC) Date: Tue, 6 Nov 2018 13:04:59 -0800 From: Andrew Morton To: Rick Edgecombe Cc: jeyu@kernel.org, willy@infradead.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, daniel@iogearbox.net, jannh@google.com, keescook@chromium.org, kristen@linux.intel.com, dave.hansen@intel.com, arjan@linux.intel.com Subject: Re: [PATCH v8 0/4] KASLR feature to randomize each loadable module Message-Id: <20181106130459.7a2669604a2c274edbe25971@linux-foundation.org> In-Reply-To: <20181102192520.4522-1-rick.p.edgecombe@intel.com> References: <20181102192520.4522-1-rick.p.edgecombe@intel.com> X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2 Nov 2018 12:25:16 -0700 Rick Edgecombe wrote: > This is V8 of the "KASLR feature to randomize each loadable module" patchset. > The purpose is to increase the randomization and also to make the modules > randomized in relation to each other instead of just the base, so that if one > module leaks the location of the others can't be inferred. I'm not seeing any info here which explains why we should add this to Linux. What is the end-user value? What problems does it solve? Are those problems real or theoretical? What are the exploit scenarios and how realistic are they? etcetera, etcetera. How are we to decide to buy this thing if we aren't given a glossy brochure? > There is a small allocation performance degradation versus v7 as a > trade off, but it is still faster on average than the existing > algorithm until >7000 modules. lol. How did you test 7000 modules? Using the selftest code?