From patchwork Fri Jan 28 18:23:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 12728916 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 EEFB9C4332F for ; Fri, 28 Jan 2022 18:24:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347788AbiA1SYY (ORCPT ); Fri, 28 Jan 2022 13:24:24 -0500 Received: from mga11.intel.com ([192.55.52.93]:26182 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343789AbiA1SYX (ORCPT ); Fri, 28 Jan 2022 13:24:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643394263; x=1674930263; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=F0TN1kp9SPJ+PH0r0h5Xs9kk0gE4PkwwlTkbFb+O0rs=; b=QOnSskvZcAQtdgk9LxCZ3qGYmXN2TBZ8Bs5JyImuseRfEz9oUbJh9uOh 8CoLN+I1nJosvWug4ijNLhPtBztdsx8UCO7y29bOwVlZ6MRKfxFKwnTP1 pfbpdlvVp47xR1Pxl/9g9bgG9FtPsVR0TitsILL1u10i1NtLbNzmWkURi NNqlFS5jUu5f1waTwk4AGn7UoHRsDlNdyUAoRzMjiTM35vmrx+Tiwtrxc xqNa9dcBSg9TXKNjiuN/YbQmgLmXQiaIeFYpWsmuvIRcqagsYt729WlKc 4vaVN/UXe/2sWYe7iF0BbOWmLLdlKGmix39Nx4V7c6c3R750eZbz0OhPX g==; X-IronPort-AV: E=McAfee;i="6200,9189,10240"; a="244773366" X-IronPort-AV: E=Sophos;i="5.88,324,1635231600"; d="scan'208";a="244773366" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2022 10:24:23 -0800 X-IronPort-AV: E=Sophos;i="5.88,324,1635231600"; d="scan'208";a="581930428" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jan 2022 10:24:23 -0800 From: Reinette Chatre To: jarkko@kernel.org, dave.hansen@linux.intel.com, linux-sgx@vger.kernel.org, shuah@kernel.org Cc: linux-kselftest@vger.kernel.org Subject: [PATCH 1/4] selftests/sgx: Fix segfault upon early test failure Date: Fri, 28 Jan 2022 10:23:56 -0800 Message-Id: <3c1d84724ecc7c94131ba1d94dc4c5de5aafc58f.1643393473.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org A segfault is encountered if there happens to be an early failure of any of the SGX tests. One way to reproduce this is to remove the enclave binary "test_encl.elf" that will trigger early enclave loading failure followed by a segfault. The segfault occurs within encl_delete() that cleans up after an enclave by umapping its mapped regions and closing the file descriptor to the SGX driver. As integrated with the kselftest harness encl_delete() is called upon exit from every test, irrespective of test success. encl_delete() is also called to clean up if an error is encountered during enclave loading. encl_delete() is thus responsible for cleaning any amount of enclave state - including state that has already been cleaned. encl_delete() starts by accessing encl->segment_tbl that may not have been created yet due to a very early failure or may already be cleaned up because of a failure encountered after encl->segment_tbl was created. Ensure encl->segment_tbl is valid before attempting to access memory offset from it. The offset with which it is accessed, encl->nr_segments, is initialized after encl->segment_tbl and thus considered valid to use after the encl->segment_tbl check succeeds. Fixes: 3200505d4de6 ("selftests/sgx: Create a heap for the test enclave") Signed-off-by: Reinette Chatre Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen --- tools/testing/selftests/sgx/load.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c index 9d4322c946e2..006b464c8fc9 100644 --- a/tools/testing/selftests/sgx/load.c +++ b/tools/testing/selftests/sgx/load.c @@ -21,7 +21,7 @@ void encl_delete(struct encl *encl) { - struct encl_segment *heap_seg = &encl->segment_tbl[encl->nr_segments - 1]; + struct encl_segment *heap_seg; if (encl->encl_base) munmap((void *)encl->encl_base, encl->encl_size); @@ -32,10 +32,11 @@ void encl_delete(struct encl *encl) if (encl->fd) close(encl->fd); - munmap(heap_seg->src, heap_seg->size); - - if (encl->segment_tbl) + if (encl->segment_tbl) { + heap_seg = &encl->segment_tbl[encl->nr_segments - 1]; + munmap(heap_seg->src, heap_seg->size); free(encl->segment_tbl); + } memset(encl, 0, sizeof(*encl)); }