From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752023AbaCBKqK (ORCPT ); Sun, 2 Mar 2014 05:46:10 -0500 Received: from mail-ee0-f54.google.com ([74.125.83.54]:57725 "EHLO mail-ee0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751769AbaCBKqI (ORCPT ); Sun, 2 Mar 2014 05:46:08 -0500 Date: Sun, 2 Mar 2014 11:46:03 +0100 From: Ingo Molnar To: Stefani Seibold Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, ak@linux.intel.com, aarcange@redhat.com, john.stultz@linaro.org, luto@amacapital.net, xemul@parallels.com, gorcunov@openvz.org, andriy.shevchenko@linux.intel.com, Martin.Runge@rohde-schwarz.com, Andreas.Brief@rohde-schwarz.com Subject: Re: [PATCH v21 12/12] x86: Zero-pad the VVAR page Message-ID: <20140302104603.GA18257@gmail.com> References: <1393752020-6740-1-git-send-email-stefani@seibold.net> <1393752020-6740-13-git-send-email-stefani@seibold.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1393752020-6740-13-git-send-email-stefani@seibold.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Stefani Seibold wrote: > By coincidence, the VVAR page is at the end of an ELF segment. As a > result, if it ends up being a partial page, the kernel loader will > leave garbage behind at the end of the vvar page. Zero-pad it to a > full page to fix this issue. > > This has probably been broken since the VVAR page was introduced. > On QEMU, if you dump the run-time contents of the VVAR page, you can > find entertaining strings from seabios left behind. > > It's remotely possible that this is a security bug -- conceivably > there's some BIOS out there that leaves something sensitive in the > few K of memory that is exposed to userspace. > > Signed-off-by: Andy Lutomirski > Signed-off-by: Stefani Seibold That's not a valid signoff sequence - if the patch came from Andy then the patch needs to contain a From: Andy line as well. If Andy acked or reviewed the patch then please add an Acked-by or Reviewed-by line. Thanks, Ingo