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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 C58F7C31E41 for ; Mon, 10 Jun 2019 16:00:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A51AE21726 for ; Mon, 10 Jun 2019 16:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390335AbfFJQAc (ORCPT ); Mon, 10 Jun 2019 12:00:32 -0400 Received: from mga18.intel.com ([134.134.136.126]:54869 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389356AbfFJQAb (ORCPT ); Mon, 10 Jun 2019 12:00:31 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jun 2019 09:00:31 -0700 X-ExtLoop1: 1 Received: from cmargarx-wtg.ger.corp.intel.com (HELO localhost) ([10.249.34.77]) by orsmga001.jf.intel.com with ESMTP; 10 Jun 2019 09:00:19 -0700 Date: Mon, 10 Jun 2019 19:00:18 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: Andy Lutomirski , Cedric Xing , Stephen Smalley , James Morris , "Serge E . Hallyn" , LSM List , Paul Moore , Eric Paris , selinux@vger.kernel.org, Jethro Beekman , Dave Hansen , Thomas Gleixner , Linus Torvalds , LKML , X86 ML , linux-sgx@vger.kernel.org, Andrew Morton , nhorman@redhat.com, npmccallum@redhat.com, Serge Ayoun , Shay Katz-zamir , Haitao Huang , Andy Shevchenko , Kai Svahn , Borislav Petkov , Josh Triplett , Kai Huang , David Rientjes , William Roberts , Philip Tricca Subject: Re: [RFC PATCH v2 3/5] x86/sgx: Enforce noexec filesystem restriction for enclaves Message-ID: <20190610160005.GC3752@linux.intel.com> References: <20190606021145.12604-1-sean.j.christopherson@intel.com> <20190606021145.12604-4-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190606021145.12604-4-sean.j.christopherson@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 Wed, Jun 05, 2019 at 07:11:43PM -0700, Sean Christopherson wrote: > + goto out; > + } > + > + /* > + * Query VM_MAYEXEC as an indirect path_noexec() check (see do_mmap()), > + * but with some future proofing against other cases that may deny > + * execute permissions. > + */ > + if (!(vma->vm_flags & VM_MAYEXEC)) { > + ret = -EACCES; > + goto out; > + } > + > + if (copy_from_user(dst, (void __user *)src, PAGE_SIZE)) > + ret = -EFAULT; > + else > + ret = 0; > + > +out: > + up_read(¤t->mm->mmap_sem); > + > + return ret; > +} I would suggest to express the above instead like this for clarity and consistency: goto err_map_sem; } /* Query VM_MAYEXEC as an indirect path_noexec() check * (see do_mmap()). */ if (!(vma->vm_flags & VM_MAYEXEC)) { ret = -EACCES; goto err_mmap_sem; } if (copy_from_user(dst, (void __user *)src, PAGE_SIZE)) { ret = -EFAULT; goto err_mmap_sem; } return 0; err_mmap_sem: up_read(¤t->mm->mmap_sem); return ret; } The comment about future proofing is unnecessary. /Jarkk