From patchwork Tue May 10 18:09:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reinette Chatre X-Patchwork-Id: 12845410 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 7E8E9C43217 for ; Tue, 10 May 2022 18:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348118AbiEJSNu (ORCPT ); Tue, 10 May 2022 14:13:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348634AbiEJSN2 (ORCPT ); Tue, 10 May 2022 14:13:28 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 970A02C130; Tue, 10 May 2022 11:09:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652206170; x=1683742170; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5wNKAhqnSZHjAufHMXeLPvtNLVlVPMc87zkkPDJvxMc=; b=Oo35goE3WEBBQuSdT6AYKUQgvtne3SAafrD48Ehx8Tl0tCa7KH0R3UPX 98ll+BE5kGu/6o6PEKGYIpKo9BOKNku8xKu1LkGlMABF42yXa6p99jPcY jARmgDKUApUL0GjKp0DZN2k1SPVEIbD6y/Us0Bluql2ISmkU4o2nHNseg lgJz8e9BLBGevo3ToGAkn5ohB5HqM0GGthLvXP7wtkqkiOXSgFz1487Ef T+OqxPzu7Q+s6pY1etUuNt4W4JUZ4gOJUoQzWqv1jCd6Tu1YJ6PMTlahK D+i7lQbsYM8iVfOwpz9BblWIW/94F8To7DpLE+t1YFYrQ9kVBj+uhYJZ/ A==; X-IronPort-AV: E=McAfee;i="6400,9594,10343"; a="330057559" X-IronPort-AV: E=Sophos;i="5.91,214,1647327600"; d="scan'208";a="330057559" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2022 11:09:18 -0700 X-IronPort-AV: E=Sophos;i="5.91,214,1647327600"; d="scan'208";a="541908846" Received: from rchatre-ws.ostc.intel.com ([10.54.69.144]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2022 11:09:17 -0700 From: Reinette Chatre To: dave.hansen@linux.intel.com, jarkko@kernel.org, tglx@linutronix.de, bp@alien8.de, luto@kernel.org, mingo@redhat.com, linux-sgx@vger.kernel.org, x86@kernel.org, shuah@kernel.org, linux-kselftest@vger.kernel.org Cc: seanjc@google.com, kai.huang@intel.com, cathy.zhang@intel.com, cedric.xing@intel.com, haitao.huang@intel.com, mark.shanahan@intel.com, vijay.dhanraj@intel.com, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: [PATCH V5 29/31] selftests/sgx: Test invalid access to removed enclave page Date: Tue, 10 May 2022 11:09:05 -0700 Message-Id: <189a86c25d6d62da7cfdd08ee97abc1a06fcc179.1652137848.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-sgx@vger.kernel.org Removing a page from an initialized enclave involves three steps: (1) the user requests changing the page type to SGX_PAGE_TYPE_TRIM via the SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), (2) on success the ENCLU[EACCEPT] instruction is run from within the enclave to accept the page removal, (3) the user initiates the actual removal of the page via the SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl(). Test two possible invalid accesses during the page removal flow: * Test the behavior when a request to remove the page by changing its type to SGX_PAGE_TYPE_TRIM completes successfully but instead of executing ENCLU[EACCEPT] from within the enclave the enclave attempts to read from the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code. * Test the behavior when the page type is changed successfully and ENCLU[EACCEPT] was run from within the enclave. The final ioctl(), SGX_IOC_ENCLAVE_REMOVE_PAGES, is omitted and replaced with an attempt to access the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code. Acked-by: Jarkko Sakkinen Signed-off-by: Reinette Chatre --- Changes since V4: - Rename struct sgx_enclave_modify_type -> struct sgx_enclave_modify_types. (Jarkko) Changes since V3: - Add Jarkko's Acked-by tag. - Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko) - User provides just page type to SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(), replacing secinfo. (Jarkko) - Let the SKIP() call involving SGX_IOC_ENCLAVE_MODIFY_TYPES span two lines to address checkpatch.pl warning triggered by new longer name. Changes since V2: - Rename struct sgx_enclave_modt -> struct sgx_enclave_modify_type Changes since V1: - Update to support ioctl() name change (SGX_IOC_PAGE_MODT -> SGX_IOC_ENCLAVE_MODIFY_TYPE) and provide secinfo as parameter instead of just page type (Jarkko). - Use ioctl() instead of ioctl (Dave). tools/testing/selftests/sgx/main.c | 243 +++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 3a82bae915d1..2c69045253b2 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -1547,4 +1547,247 @@ TEST_F(enclave, remove_added_page_no_eaccept) EXPECT_EQ(remove_ioc.count, 0); } +/* + * Request enclave page removal but instead of correctly following with + * EACCEPT a read attempt to page is made from within the enclave. + */ +TEST_F(enclave, remove_added_page_invalid_access) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct sgx_enclave_modify_types ioc; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&ioc, 0, sizeof(ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Page that will be removed is the second data page in the .data + * segment. This forms part of the local encl_buffer within the + * enclave. + */ + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before + * removing it. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that data + * previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Start page removal by requesting change of page type to PT_TRIM. */ + memset(&ioc, 0, sizeof(ioc)); + + ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + ioc.length = PAGE_SIZE; + ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(ioc.result, 0); + EXPECT_EQ(ioc.count, 4096); + + /* + * Read from page that was just removed. + */ + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + /* + * From kernel perspective the page is present but according to SGX the + * page should not be accessible so a #PF with SGX bit set is + * expected. + */ + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x8005); + EXPECT_EQ(self->run.exception_addr, data_start); +} + +/* + * Request enclave page removal and correctly follow with + * EACCEPT but do not follow with removal ioctl() but instead a read attempt + * to removed page is made from within the enclave. + */ +TEST_F(enclave, remove_added_page_invalid_access_after_eaccept) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + struct sgx_enclave_modify_types ioc; + struct encl_op_eaccept eaccept_op; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&ioc, 0, sizeof(ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, + "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* + * Page that will be removed is the second data page in the .data + * segment. This forms part of the local encl_buffer within the + * enclave. + */ + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + PAGE_SIZE; + + /* + * Sanity check that page at @data_start is writable before + * removing it. + * + * Start by writing MAGIC to test page. + */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that data + * previously written (MAGIC) is present. + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Start page removal by requesting change of page type to PT_TRIM. */ + memset(&ioc, 0, sizeof(ioc)); + + ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + ioc.length = PAGE_SIZE; + ioc.page_type = SGX_PAGE_TYPE_TRIM; + + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &ioc); + errno_save = ret == -1 ? errno : 0; + + EXPECT_EQ(ret, 0); + EXPECT_EQ(errno_save, 0); + EXPECT_EQ(ioc.result, 0); + EXPECT_EQ(ioc.count, 4096); + + eaccept_op.epc_addr = (unsigned long)data_start; + eaccept_op.ret = 0; + eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED; + eaccept_op.header.type = ENCL_OP_EACCEPT; + + EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + EXPECT_EQ(eaccept_op.ret, 0); + + /* Skip ioctl() to remove page. */ + + /* + * Read from page that was just removed. + */ + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + /* + * From kernel perspective the page is present but according to SGX the + * page should not be accessible so a #PF with SGX bit set is + * expected. + */ + + EXPECT_EQ(self->run.function, ERESUME); + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x8005); + EXPECT_EQ(self->run.exception_addr, data_start); +} + TEST_HARNESS_MAIN