From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753448AbaLUKSf (ORCPT ); Sun, 21 Dec 2014 05:18:35 -0500 Received: from mail-wi0-f176.google.com ([209.85.212.176]:37349 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751020AbaLUKSc (ORCPT ); Sun, 21 Dec 2014 05:18:32 -0500 Date: Sun, 21 Dec 2014 11:18:27 +0100 From: Ingo Molnar To: Andy Lutomirski Cc: X86 ML , "linux-kernel@vger.kernel.org" , Kees Cook Subject: Re: [GIT PULL] one vdso fix for x86/urgent Message-ID: <20141221101827.GA769@gmail.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski wrote: > Hi Ingo, etc, > > Please consider pulling for x86/urgent. This fixes a longstanding, > albeit relatively minor, issue in the x86 vdso randomization > algorithm. Note that this isn't super-urgent, as this bug isn't > directly exploitable, and it's as old as the vdso itself. > > Thanks, > Andy > > The following changes since commit e589c9e13aeb0c5539bf1314b3a78442ea8fc0c2: > > Merge branch 'x86-apic-for-linus' of > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (2014-12-19 > 14:02:02 -0800) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git > tags/pr-20141220-x86-vdso > > for you to fetch changes up to 394f56fe480140877304d342dec46d50dc823d46: > > x86_64, vdso: Fix the vdso address randomization algorithm > (2014-12-20 16:56:57 -0800) > > ---------------------------------------------------------------- > One vdso fix for a longstanding ASLR bug that's been in the news lately. > > The vdso base address has always been randomized, and I don't think there's > anything particularly wrong with the range over which it's randomized, > but the implementation seems to have been buggy since the very beginning. > > This fixes the implementation to remove a large bias that caused a small > fraction of possible vdso load addresess to be vastly more likely than > the rest of the possible addresses. > > ---------------------------------------------------------------- > Andy Lutomirski (1): > x86_64, vdso: Fix the vdso address randomization algorithm > > arch/x86/vdso/vma.c | 45 +++++++++++++++++++++++++++++---------------- > 1 file changed, 29 insertions(+), 16 deletions(-) Pulled into tip:x86/urgent, thanks a lot Andy! Ingo