Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752367AbaANXpt (ORCPT ); Tue, 14 Jan 2014 18:45:49 -0500 Received: from mga03.intel.com ([143.182.124.21]:17186 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752114AbaANXpr (ORCPT ); Tue, 14 Jan 2014 18:45:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,659,1384329600"; d="scan'208";a="458861943" Message-ID: <52D5CC2A.7030906@linux.intel.com> Date: Tue, 14 Jan 2014 15:45:46 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Kees Cook CC: Fengguang Wu , LKML Subject: Re: [x86, kaslr] BUG: kernel boot hang References: <20140114133125.GB26942@localhost> <52D5C6F2.7090607@linux.intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/14/2014 03:31 PM, Kees Cook wrote: > On Tue, Jan 14, 2014 at 3:23 PM, H. Peter Anvin wrote: >> On 01/14/2014 02:33 PM, Kees Cook wrote: >>> >>> Can you tell me how the initrd for quantal-core-x86_64.cgz was built >>> in the qemu instances you're using? It seems like all the failures >>> point to a problem with how kASLR is interacting with the initrd. >>> >> >> If kASLR somehow causes the kernel to collide with the initrd that would >> be problem... > > Agreed, but I can't reproduce this yet. The initrd is on the list of > areas that get avoided, so the fundamental design isn't broken, but > clearly something is busted. > > How long has tip:x86/kaslr been sitting in linux-next? If this is some > interaction between kaslr and something else, perhaps merge order just > happens to be pointing at kaslr? > > Regardless, all my tests so far against next-20140114 and an initramfs > haven't seen corruption (using the given .config). I don't have the > same initrd, though, so I'm hoping getting that will trigger the > glitch. > Given our craptastic ELF parser I'm wondering if we at some point overrun the kernel "safe memory zone" during decompression/parsing... -hpa -- 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/