From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761860AbdACXTg (ORCPT ); Tue, 3 Jan 2017 18:19:36 -0500 Received: from mail-io0-f175.google.com ([209.85.223.175]:33326 "EHLO mail-io0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753269AbdACXT2 (ORCPT ); Tue, 3 Jan 2017 18:19:28 -0500 MIME-Version: 1.0 In-Reply-To: References: <20161217010127.GA140378@beast> From: Kees Cook Date: Tue, 3 Jan 2017 15:19:26 -0800 X-Google-Sender-Auth: 9aOt0tH0TCjRK0J3_pI-0tu-JoY 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 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. > 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.) -Kees -- Kees Cook Nexus Security