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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 2F8D9C282CE for ; Mon, 3 Jun 2019 22:27:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F61623A46 for ; Mon, 3 Jun 2019 22:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726097AbfFCW1Z (ORCPT ); Mon, 3 Jun 2019 18:27:25 -0400 Received: from mga18.intel.com ([134.134.136.126]:27917 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726025AbfFCW1Z (ORCPT ); Mon, 3 Jun 2019 18:27:25 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jun 2019 14:05:46 -0700 X-ExtLoop1: 1 Received: from jgaire-mobl.ger.corp.intel.com (HELO localhost) ([10.252.20.169]) by fmsmga005.fm.intel.com with ESMTP; 03 Jun 2019 14:05:35 -0700 Date: Tue, 4 Jun 2019 00:05:34 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: Andy Lutomirski , Stephen Smalley , "Xing, Cedric" , William Roberts , James Morris , "Serge E. Hallyn" , LSM List , Paul Moore , Eric Paris , "selinux@vger.kernel.org" , Jethro Beekman , "Hansen, Dave" , Thomas Gleixner , "Dr. Greg" , Linus Torvalds , LKML , X86 ML , "linux-sgx@vger.kernel.org" , Andrew Morton , "nhorman@redhat.com" , "npmccallum@redhat.com" , "Ayoun, Serge" , "Katz-zamir, Shay" , "Huang, Haitao" , Andy Shevchenko , "Svahn, Kai" , Borislav Petkov , Josh Triplett , "Huang, Kai" , David Rientjes Subject: Re: SGX vs LSM (Re: [PATCH v20 00/28] Intel SGX1 support) Message-ID: <20190603210534.GF4894@linux.intel.com> References: <960B34DE67B9E140824F1DCDEC400C0F654E9824@ORSMSX116.amr.corp.intel.com> <20190528202407.GB13158@linux.intel.com> <285f279f-b500-27f0-ab42-fb1dbcc5ab18@tycho.nsa.gov> <960B34DE67B9E140824F1DCDEC400C0F654EB487@ORSMSX116.amr.corp.intel.com> <678a37af-797d-7bd5-a406-32548a270e3d@tycho.nsa.gov> <20190530180110.GB23930@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190530180110.GB23930@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Thu, May 30, 2019 at 11:01:10AM -0700, Sean Christopherson wrote: > - Requires enclave builder to mark enclave pages executable in the > non-enclave VMAs, which may unnecessarily require EXECMOD on the > source file, or even worse, EXECMEM, and potentially increases the > attack surface since the file must be executable. Enclave builder marks *non-enclave pages*? Not following. > W^X handling: > - mmap() to /dev/sgx/enclave only allowed with PROT_NONE, i.e. force > userspace through mprotect() to simplify the kernel implementation. > - Add vm_ops mprotect() ops hook (I'll refer to SGX's implementation > as SGX.mprotect()) > - Take explicit ALLOW_WRITE at ADD_REGION, a.k.a. EADD > - ADD_REGION also used to describe EAUG region (tentatively for SGX2). > - Track "can be written at some point in time (past or future)" as > ALLOW_WRITE (to avoid confusiong with MAY_WRITE). A priori knowledge > of writability avoids having to track/coordinate PROT_WRITE across > VMAs and MMs. Still not sure why you want to use vm_ops instead of file_operations. The approach I've been proposing earlier in this email thread before these new proposals can be summarized from hook perspective as: - Allow mmap() only before ECREATE and require it to be size of the ELRANGE (ECREATE ioctl would check this). This would be with PROT_NONE. - Disallow mprotect() before EINIT. Requires a new callback to file_operations like mmap() has. - After EINIT check for each mprotect() that it matches the permissions of underlying enclave pages. Disallow mmap() after EINIT. /Jarkko