From patchwork Tue Jul 18 02:49:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13316699 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 AD449EB64DC for ; Tue, 18 Jul 2023 02:49:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230339AbjGRCto (ORCPT ); Mon, 17 Jul 2023 22:49:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229786AbjGRCto (ORCPT ); Mon, 17 Jul 2023 22:49:44 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48C5D19F; Mon, 17 Jul 2023 19:49:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689648583; x=1721184583; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=TBlnlo2O0N/Bg2K7ED4/hpZpPRItIwwkMy25tQllHVE=; b=MvTumbGl7YzHH0Wya9hGoHHO5W4iB8BeD4I+eVHzdQ9l0U5RM0KZqMN2 hkkOFAzs70R3ccxeYT0TUylaGlgjvuTty5HDd/kxqZmVoZrj8h9wnW0PO PqLI62yU5nhmv+qRmjUD5dBIL56VbxDJ3RYfEF8rQDTmHpq6lMqe+7OVA /oP7DR4ECFl+yM5n/7SBHfBsOPSoRhuUeQR4vFXnrWW+UhDsoUwEmBXrt b7pkx+9OYs5qCbL8xsrkKj9XSHxjVBu34w0grBM1IKmD96ej4Zy1xhGNF 5Ej5sxel9zy/q0o6Cytgmp3GBxhiNKJP1e02y8O085ZAK3Iy3iLjFuxp+ w==; X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="452469926" X-IronPort-AV: E=Sophos;i="6.01,213,1684825200"; d="scan'208";a="452469926" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2023 19:49:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="847532876" X-IronPort-AV: E=Sophos;i="6.01,213,1684825200"; d="scan'208";a="847532876" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by orsmga004.jf.intel.com with ESMTP; 17 Jul 2023 19:49:42 -0700 From: Haitao Huang To: jarkko@kernel.org, dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" Cc: kai.huang@intel.com, reinette.chatre@intel.com, kristen@linux.intel.com, seanjc@google.com, stable@vger.kernel.org Subject: [PATCH v2] x86/sgx: fix a NULL pointer Date: Mon, 17 Jul 2023 19:49:42 -0700 Message-Id: <20230718024942.99808-1-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 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(-) base-commit: 6995e2de6891c724bfeb2db33d7b87775f913ad1 diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 2a0e90fe2abc..d3b099c75f40 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)