From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91B5DC433B4 for ; Thu, 1 Apr 2021 08:38:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A4E460190 for ; Thu, 1 Apr 2021 08:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233283AbhDAIiZ (ORCPT ); Thu, 1 Apr 2021 04:38:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:33690 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233024AbhDAIiL (ORCPT ); Thu, 1 Apr 2021 04:38:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C6D0B61041; Thu, 1 Apr 2021 08:38:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617266286; bh=pL7zEm/CJ6Uq13TbvMopTgicNXFZzItUs41gFNFs0bo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A3X3lduCFkIuAeuQcqpzhul7wvKwDj5UjZ40gX0BhH6coMkam04N1fMhBXiO1k9fr Qx/8Cp+zmkSw5yt/9WD3OWEBwEdVVUiTgmrKXPktPG5MJhpkzp1IqJLPCbqq2ePs32 NzwqEkscV/FJQFSYJe0Z+pA7s1+1j2kz8cRLj9B2ZGRPbxRir0oMbkz4NORBnn08Qw zpEovn8ARnysgKDkNQpa5nWT4UqQLnGUIgZL92lSn8A0CTU6eFdvu51VF/lz3gas5G NbEBSMnsjL1na3BP/51tBCx3wTgdCqXYFtiXlE20KJqh/YGMRt2tzdaxvdOsy5SBYF Da/Tpgqva8b+A== Date: Thu, 1 Apr 2021 09:37:59 +0100 From: Will Deacon To: Kees Cook Cc: Catalin Marinas , Mark Rutland , Thomas Gleixner , Elena Reshetova , x86@kernel.org, Andy Lutomirski , Peter Zijlstra , Alexander Potapenko , Alexander Popov , Ard Biesheuvel , Jann Horn , Vlastimil Babka , David Hildenbrand , Mike Rapoport , Andrew Morton , Jonathan Corbet , Randy Dunlap , kernel-hardening@lists.openwall.com, linux-hardening@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v9 0/6] Optionally randomize kernel stack offset each syscall Message-ID: <20210401083758.GA8745@willie-the-truck> References: <20210331205458.1871746-1-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210331205458.1871746-1-keescook@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Hi Kees, On Wed, Mar 31, 2021 at 01:54:52PM -0700, Kees Cook wrote: > Hi Will (and Mark and Catalin), > > Can you take this via the arm64 tree for v5.13 please? Thomas has added > his Reviewed-by, so it only leaves arm64's. :) Sorry, these got mixed up in my inbox so I just replied to v7 and v8 and then noticed v9. Argh! However, I think the comments still apply: namely that the dummy "=m" looks dangerous to me and I think you're accessing pcpu variables with preemption enabled for the arm64 part: https://lore.kernel.org/r/20210401083034.GA8554@willie-the-truck https://lore.kernel.org/r/20210401083430.GB8554@willie-the-truck Will