From patchwork Tue Jul 18 00:45:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13316650 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2666FEB64DC for ; Tue, 18 Jul 2023 00:45:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229706AbjGRApc (ORCPT ); Mon, 17 Jul 2023 20:45:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229517AbjGRApb (ORCPT ); Mon, 17 Jul 2023 20:45:31 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80C2F10DF; Mon, 17 Jul 2023 17:45:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689641130; x=1721177130; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8hmovxAM62OkfQ6A1m8pIfWHXBwPK8Mh/VcMsgXwkkk=; b=kdflyR6+NhV5YkbRDcm/FBy/oeB12OpQ7My21T2QogQEGm5gJx0bNgeK GTiPWsIrND3W0sfcEq/MqtFc50DWyQCeEDu2GX/Qg2CxNtMP0T38MYN9D yAsDiUUNK7XV6SdOZL8kK2LDFdUXC+ZhV8eLGzQhLLuXgygFfN+IGgMNq kB1KBjm/O2aJ4GtA+HrZmCogIRZGcb5SEdx/xJnkMI+g8QNKhV2+L/mV7 4nR6ostU6Y60Cwss+wyvJSkAziC9HFnNwpD/AhWptDyNDCGsWzH84tdGd a1DJvygrfDIzcYGGY+1cdevfku+6WyTsiBZMT7BB9tymOoAdfwfCMXbhk w==; X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="368716729" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="368716729" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2023 17:45:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="897381841" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="897381841" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by orsmga005.jf.intel.com with ESMTP; 17 Jul 2023 17:45:29 -0700 From: Haitao Huang To: kai.huang@intel.com, "linux-sgx@vger.kernel.org" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "jarkko@kernel.org" , "x86@kernel.org" , "mingo@redhat.com" , "tglx@linutronix.de" , "hpa@zytor.com" , "haitao.huang@linux.intel.com" , "linux-kernel@vger.kernel.org" Cc: "kristen@linux.intel.com" , "Chatre, Reinette" , "stable@vger.kernel.org" , "Christopherson,, Sean" Subject: [PATCH] x86/sgx: fix a NULL pointer Date: Mon, 17 Jul 2023 17:45:29 -0700 Message-Id: <20230718004529.16404-1-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <38deca3161bd4c5f1698fd7b6c43aa3c7b94d3da.camel@intel.com> References: <38deca3161bd4c5f1698fd7b6c43aa3c7b94d3da.camel@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Under heavy load, the SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an enclave and set encl->secs.epc_page to NULL. But the SECS EPC page is used for EAUG in the SGX #PF handler without checking for NULL and reloading. Fix this by checking if SECS is loaded before EAUG and loading it if it was reclaimed. Fixes: 5a90d2c3f5ef ("x86/sgx: Support adding of pages to an initialized enclave") Cc: stable@vger.kernel.org Signed-off-by: Haitao Huang --- arch/x86/kernel/cpu/sgx/encl.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 2a0e90fe2abc..2ab544da1664 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -235,6 +235,16 @@ static struct sgx_epc_page *sgx_encl_eldu(struct sgx_encl_page *encl_page, return epc_page; } +static struct sgx_epc_page *sgx_encl_load_secs(struct sgx_encl *encl) +{ + struct sgx_epc_page *epc_page = encl->secs.epc_page; + + if (!epc_page) + epc_page = sgx_encl_eldu(&encl->secs, NULL); + + return epc_page; +} + static struct sgx_encl_page *__sgx_encl_load_page(struct sgx_encl *encl, struct sgx_encl_page *entry) { @@ -248,11 +258,9 @@ static struct sgx_encl_page *__sgx_encl_load_page(struct sgx_encl *encl, return entry; } - if (!(encl->secs.epc_page)) { - epc_page = sgx_encl_eldu(&encl->secs, NULL); - if (IS_ERR(epc_page)) - return ERR_CAST(epc_page); - } + epc_page = sgx_encl_load_secs(encl); + if (IS_ERR(epc_page)) + return ERR_CAST(epc_page); epc_page = sgx_encl_eldu(entry, encl->secs.epc_page); if (IS_ERR(epc_page)) @@ -339,6 +347,13 @@ static vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, mutex_lock(&encl->lock); + epc_page = sgx_encl_load_secs(encl); + if (IS_ERR(epc_page)) { + if (PTR_ERR(epc_page) == -EBUSY) + vmret = VM_FAULT_NOPAGE; + goto err_out_unlock; + } + epc_page = sgx_alloc_epc_page(encl_page, false); if (IS_ERR(epc_page)) { if (PTR_ERR(epc_page) == -EBUSY)