Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751949AbaANScJ (ORCPT ); Tue, 14 Jan 2014 13:32:09 -0500 Received: from mail-ob0-f172.google.com ([209.85.214.172]:49396 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751472AbaANScH (ORCPT ); Tue, 14 Jan 2014 13:32:07 -0500 MIME-Version: 1.0 In-Reply-To: <52D55F92.8040108@linux.intel.com> References: <20140114133125.GB26942@localhost> <52D55F92.8040108@linux.intel.com> Date: Tue, 14 Jan 2014 10:32:06 -0800 X-Google-Sender-Auth: yOgPg_IJx83N-jJ5EB14mktWtYw Message-ID: Subject: Re: [x86, kaslr] BUG: kernel boot hang From: Kees Cook To: "H. Peter Anvin" Cc: Fengguang Wu , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 14, 2014 at 8:02 AM, H. Peter Anvin wrote: > On 01/14/2014 05:31 AM, Fengguang Wu wrote: >> Greetings, >> >> I got the below dmesg and the first bad commit is >> >> commit 82fa9637a2ba285bcc7c5050c73010b2c1b3d803 >> Author: Kees Cook >> AuthorDate: Thu Oct 10 17:18:16 2013 -0700 >> Commit: H. Peter Anvin >> CommitDate: Sun Oct 13 03:12:19 2013 -0700 >> >> x86, kaslr: Select random position from e820 maps >> >> Counts available alignment positions across all e820 maps, and chooses >> one randomly for the new kernel base address, making sure not to collide >> with unsafe memory areas. >> >> Signed-off-by: Kees Cook >> Link: http://lkml.kernel.org/r/1381450698-28710-5-git-send-email-keescook@chromium.org >> Signed-off-by: H. Peter Anvin >> >> Note that there are many other warning/errors and it's not very >> reproducible, so this report might be wrong. >> >> =================================================== >> PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT! >> =================================================== >> > > I wonder if this is in any way related to the fact that the ELF parser > we have in the decompressor is quite frankly complete crap... it assumes > that all sections can only be moved downward. Not that this would change the code here, but I notice tip:x86/kaslr isn't fully up to date. It's still missing the two most recent commits: https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=kaslr-c-v8 "x86, kaslr: clarify RANDOMIZE_BASE_MAX_OFFSET" "x86, kaslr: remove unused including " -Kees -- Kees Cook Chrome OS Security -- 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/