From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932585AbcI1NTQ (ORCPT ); Wed, 28 Sep 2016 09:19:16 -0400 Received: from albireo.enyo.de ([5.158.152.32]:54752 "EHLO albireo.enyo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932302AbcI1NTJ (ORCPT ); Wed, 28 Sep 2016 09:19:09 -0400 X-Greylist: delayed 358 seconds by postgrey-1.27 at vger.kernel.org; Wed, 28 Sep 2016 09:19:09 EDT From: Florian Weimer To: Jason Gunthorpe Cc: Michael Ellerman , Florian Weimer , Denys Vlasenko , Kees Cook , Oleg Nesterov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Paul Mackerras , Al Viro , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: Re: [PATCH v5] powerpc: Do not make the entire heap executable References: <20160822185105.29600-1-dvlasenk@redhat.com> <87d1jo7qbw.fsf@concordia.ellerman.id.au> <20160928025544.GA24199@obsidianresearch.com> Date: Wed, 28 Sep 2016 15:12:57 +0200 In-Reply-To: <20160928025544.GA24199@obsidianresearch.com> (Jason Gunthorpe's message of "Tue, 27 Sep 2016 20:55:44 -0600") Message-ID: <87k2dwgobq.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jason Gunthorpe: > Eg that 32 bit powerpc currently unconditionally injects writable, > executable pages into a user space process. > > This critically undermines all the W^X security work that has been > done in the tool chain and user space by the PPC community. Exactly, this is how we found it. I have pretty extensive execmod tests, and I'm going to put them into glibc eventually. It would be nice to cut down the number of architectures where it will fail. (Even if you don't believe in security hardening.)