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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 ED81DC00454 for ; Mon, 9 Dec 2019 19:08:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9A7A20692 for ; Mon, 9 Dec 2019 19:08:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbfLITIm (ORCPT ); Mon, 9 Dec 2019 14:08:42 -0500 Received: from mga09.intel.com ([134.134.136.24]:25524 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726365AbfLITIl (ORCPT ); Mon, 9 Dec 2019 14:08:41 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Dec 2019 11:08:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,296,1571727600"; d="scan'208";a="210202854" Received: from nshalmon-mobl.ger.corp.intel.com (HELO localhost) ([10.252.8.146]) by fmsmga008.fm.intel.com with ESMTP; 09 Dec 2019 11:08:31 -0800 Date: Mon, 9 Dec 2019 21:08:29 +0200 From: Jarkko Sakkinen To: Haitao Huang Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, linux-security-module@vger.kernel.org, Suresh Siddha Subject: Re: [PATCH v24 12/24] x86/sgx: Linux Enclave Driver Message-ID: <20191209182219.GA19243@linux.intel.com> References: <20191129231326.18076-1-jarkko.sakkinen@linux.intel.com> <20191129231326.18076-13-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 02, 2019 at 09:48:43AM -0600, Haitao Huang wrote: > On Fri, 29 Nov 2019 17:13:14 -0600, Jarkko Sakkinen > wrote: > > > > + > > + for (c = 0 ; c < addp.length; c += PAGE_SIZE) { > > + if (signal_pending(current)) { > > + ret = -ERESTARTSYS; > > + break; > > + } > > This IOC is not idempotent as pages EADDed at this point can not be > re-EADDed again. So we can't return ERESTARTSYS Agreed, should be -EINTR. I added these entries to the v25 change log based on your recent reports: * Fix a double-free issue when SGX_IOC_ENCLAVE_ADD_PAGES fails on executing ENCLS[EADD]. The rollback path executed radix_tree_delete() on the same address twice when this happened. [fixes v24, reported by Haitao] * Return -EINTR instead of -ERESTARTSYS in SGX_IOC_ENCLAVE_ADD_PAGES when a signal is pending [fixes v23, reported by Haitao] The master branch [1] has been updated accordingly. There is also a tag v24 for looking up easily what has overally changed e.g. $ git --no-pager diff v24..master diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index ab9e48cd294b..5c9e6e161698 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -413,13 +413,8 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, ret = __sgx_encl_add_page(encl, encl_page, epc_page, secinfo, src); - if (ret) { - /* ENCLS failure. */ - if (ret == -EIO) - sgx_encl_destroy(encl); - + if (ret) goto err_out; - } /* * Complete the "add" before doing the "extend" so that the "add" @@ -432,17 +427,11 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, if (flags & SGX_PAGE_MEASURE) { ret = __sgx_encl_extend(encl, epc_page); - - /* ENCLS failure. */ - if (ret) { - sgx_encl_destroy(encl); - goto out_unlock; - } + if (ret) + goto err_out; } sgx_mark_page_reclaimable(encl_page->epc_page); - -out_unlock: mutex_unlock(&encl->lock); up_read(¤t->mm->mmap_sem); return ret; @@ -460,6 +449,13 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, sgx_free_page(epc_page); kfree(encl_page); + /* + * Destroy enclave on ENCLS failure as this means that EPC has been + * invalidated. + */ + if (ret == -EIO) + sgx_encl_destroy(encl); + return ret; } @@ -536,7 +532,7 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) for (c = 0 ; c < addp.length; c += PAGE_SIZE) { if (signal_pending(current)) { - ret = -ERESTARTSYS; + ret = -EINTR; break; } [1] https://github.com/jsakkine-intel/linux-sgx /Jarkko