From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932934AbdC2Usq (ORCPT ); Wed, 29 Mar 2017 16:48:46 -0400 Received: from mail-io0-f171.google.com ([209.85.223.171]:36709 "EHLO mail-io0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932748AbdC2Usb (ORCPT ); Wed, 29 Mar 2017 16:48:31 -0400 MIME-Version: 1.0 In-Reply-To: References: <20161217010127.GA140378@beast> From: Kees Cook Date: Wed, 29 Mar 2017 13:48:29 -0700 X-Google-Sender-Auth: FB2dhAEHCrzSvGoNkVCsfj8yMqA Message-ID: Subject: Re: [PATCH] sgi-xp: use designated initializers To: Robin Holt Cc: LKML , Cliff Whickman 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 3, 2017 at 3:19 PM, Kees Cook wrote: > On Wed, Dec 21, 2016 at 8:24 AM, Robin Holt wrote: >> On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook wrote: >>> Prepare to mark sensitive kernel structures for randomization by making >>> sure they're using designated initializers. These were identified during >>> allyesconfig builds of x86, arm, and arm64, with most initializer fixes >>> extracted from grsecurity. >> >> I guess I don't understand the context enough here to give you a >> Signed-off-by. Can you give us more background on this randomization? > > Sure thing! The randomization is on the order of function pointers in > all-pointer structures (like struct xpc_interface). As long as the > memory containing the structure isn't shared externally, this > randomization should have no operational effect. The reason explicit > no-op functions were added was to avoid ugly casts, etc. Friendly ping ... any chance this can land in -next soon? >> From what I see in the code here, I can see you are providing >> equivalent functionality and I would give it a signed-off-by, but I am >> not sure this randomization of which you speak is not going to cause >> problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel >> module). > > Ah, hm, does this module share the structure without being built > against the kernel? (If built with the kernel, the randomization > plugin will keep things in the right order.) Regardless of your answer, this randomization can be turned off. Switching to designated initializers here is mainly just a clean up. Thanks! -Kees -- Kees Cook Pixel Security