Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752610Ab0KTLeN (ORCPT ); Sat, 20 Nov 2010 06:34:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:6817 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752428Ab0KTLeL (ORCPT ); Sat, 20 Nov 2010 06:34:11 -0500 Message-ID: <4CE7B1CF.8060300@redhat.com> Date: Sat, 20 Nov 2010 13:32:31 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101103 Fedora/1.0-0.33.b2pre.fc14 Thunderbird/3.1.6 MIME-Version: 1.0 To: Kyle Moffett CC: Marcus Meissner , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, tj@kernel.org, akpm@osdl.org, hpa@zytor.com, mingo@elte.hu, w@1wt.eu, alan@lxorguk.ukuu.org.uk Subject: Re: [PATCH] kernel: make /proc/kallsyms mode 400 to reduce ease of attacking References: <20101116104600.GA24015@suse.de> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1118 Lines: 23 On 11/17/2010 07:40 AM, Kyle Moffett wrote: > (1) For 99%+ of all the computers out there you can get a 90%+ > accurate guess for what kernel is running by looking at the version of > libc installed on the system. All you have to do for those computers > is download a bunch of distro kernels and look at the libc packages > and build a table of "libc6-SOMEVERSION => 0xADDRESS", etc. Because > of how all the vendors backport and track versions, "SOMEVERSION" > usually includes something wonderfully helpful like "el5" or "squeeze" > or whatever. This does *nothing* for those users, and it's not clear > that it ever *could*. Isn't the kernel relocatable these days? We can randomize the kernel load address at boot time and make this information useless. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/