From patchwork Tue Sep 3 14:26:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11128053 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E5EEC1395 for ; Tue, 3 Sep 2019 14:29:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C729723774 for ; Tue, 3 Sep 2019 14:29:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729113AbfICO3C (ORCPT ); Tue, 3 Sep 2019 10:29:02 -0400 Received: from mga11.intel.com ([192.55.52.93]:49729 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729079AbfICO3C (ORCPT ); Tue, 3 Sep 2019 10:29:02 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 07:29:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,463,1559545200"; d="scan'208";a="189826072" Received: from vkuppusa-mobl2.ger.corp.intel.com (HELO localhost) ([10.252.39.67]) by FMSMGA003.fm.intel.com with ESMTP; 03 Sep 2019 07:28:52 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: 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, Jarkko Sakkinen , James Morris , "Serge E . Hallyn" , linux-security-module@vger.kernel.org Subject: [PATCH v22 13/24] x86/sgx: Add provisioning Date: Tue, 3 Sep 2019 17:26:44 +0300 Message-Id: <20190903142655.21943-14-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903142655.21943-1-jarkko.sakkinen@linux.intel.com> References: <20190903142655.21943-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: In order to provide a mechanism for devilering provisoning rights: 1. Add a new device file /dev/sgx/provision that works as a token for allowing an enclave to have the provisioning privileges. 2. Add a new ioctl called SGX_IOC_ENCLAVE_SET_ATTRIBUTE that accepts the following data structure: struct sgx_enclave_set_attribute { __u64 addr; __u64 attribute_fd; }; A daemon could sit on top of /dev/sgx/provision and send a file descriptor of this file to a process that needs to be able to provision enclaves. The way this API is used is straight-forward. Lets assume that dev_fd is a handle to /dev/sgx/enclave and prov_fd is a handle to /dev/sgx/provision. You would allow SGX_IOC_ENCLAVE_CREATE to initialize an enclave with the PROVISIONKEY attribute by params.addr = ; params.token_fd = prov_fd; ioctl(dev_fd, SGX_IOC_ENCLAVE_SET_ATTRIBUTE, ¶ms); Cc: James Morris Cc: Serge E. Hallyn Cc: linux-security-module@vger.kernel.org Suggested-by: Andy Lutomirski Signed-off-by: Jarkko Sakkinen --- arch/x86/include/uapi/asm/sgx.h | 11 +++++++ arch/x86/kernel/cpu/sgx/driver.c | 23 ++++++++++++++- arch/x86/kernel/cpu/sgx/driver.h | 2 +- arch/x86/kernel/cpu/sgx/ioctl.c | 49 +++++++++++++++++++++++++++++++- 4 files changed, 82 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index c45eeed68144..420001ac205e 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -16,6 +16,8 @@ _IOW(SGX_MAGIC, 0x01, struct sgx_enclave_add_page) #define SGX_IOC_ENCLAVE_INIT \ _IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init) +#define SGX_IOC_ENCLAVE_SET_ATTRIBUTE \ + _IOW(SGX_MAGIC, 0x03, struct sgx_enclave_set_attribute) /** * struct sgx_enclave_create - parameter structure for the @@ -52,4 +54,13 @@ struct sgx_enclave_init { __u64 sigstruct; }; +/** + * struct sgx_enclave_set_attribute - parameter structure for the + * %SGX_IOC_ENCLAVE_SET_ATTRIBUTE ioctl + * @attribute_fd: file handle of the attribute file in the securityfs + */ +struct sgx_enclave_set_attribute { + __u64 attribute_fd; +}; + #endif /* _UAPI_ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index 3eb45bdf9826..f046518cbdf6 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -140,12 +140,18 @@ static const struct file_operations sgx_encl_fops = { .get_unmapped_area = sgx_get_unmapped_area, }; +const struct file_operations sgx_provision_fops = { + .owner = THIS_MODULE, +}; + static struct bus_type sgx_bus_type = { .name = "sgx", }; static struct device sgx_encl_dev; static struct cdev sgx_encl_cdev; +static struct device sgx_provision_dev; +static struct cdev sgx_provision_cdev; static dev_t sgx_devt; static void sgx_dev_release(struct device *dev) @@ -222,22 +228,37 @@ int __init sgx_drv_init(void) if (ret) goto err_chrdev_region; + ret = sgx_dev_init("sgx/provision", &sgx_provision_dev, + &sgx_provision_cdev, &sgx_provision_fops, 1); + if (ret) + goto err_encl_dev; + sgx_encl_wq = alloc_workqueue("sgx-encl-wq", WQ_UNBOUND | WQ_FREEZABLE, 1); if (!sgx_encl_wq) { ret = -ENOMEM; - goto err_encl_dev; + goto err_provision_dev; } ret = cdev_device_add(&sgx_encl_cdev, &sgx_encl_dev); if (ret) goto err_encl_wq; + ret = cdev_device_add(&sgx_provision_cdev, &sgx_provision_dev); + if (ret) + goto err_encl_cdev; + return 0; +err_encl_cdev: + cdev_device_del(&sgx_encl_cdev, &sgx_encl_dev); + err_encl_wq: destroy_workqueue(sgx_encl_wq); +err_provision_dev: + put_device(&sgx_provision_dev); + err_encl_dev: put_device(&sgx_encl_dev); diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h index b045b1fcf258..1e35933cf8a4 100644 --- a/arch/x86/kernel/cpu/sgx/driver.h +++ b/arch/x86/kernel/cpu/sgx/driver.h @@ -28,7 +28,7 @@ extern u64 sgx_attributes_reserved_mask; extern u64 sgx_xfrm_reserved_mask; extern u32 sgx_xsave_size_tbl[64]; -extern const struct file_operations sgx_fs_provision_fops; +extern const struct file_operations sgx_provision_fops; long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg); diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index b2603db60c43..2fcdd080158e 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -159,7 +159,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) encl->secs.encl = encl; encl->secs_attributes = secs->attributes; - encl->allowed_attributes = SGX_ATTR_ALLOWED_MASK; + encl->allowed_attributes |= SGX_ATTR_ALLOWED_MASK; encl->base = secs->base; encl->size = secs->size; encl->ssaframesize = secs->ssa_frame_size; @@ -578,6 +578,50 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) return ret; } +/** + * sgx_ioc_enclave_set_attribute - handler for %SGX_IOC_ENCLAVE_SET_ATTRIBUTE + * @filep: open file to /dev/sgx + * @arg: userspace pointer to a struct sgx_enclave_set_attribute instance + * + * Mark the enclave as being allowed to access a restricted attribute bit. + * The requested attribute is specified via the attribute_fd field in the + * provided struct sgx_enclave_set_attribute. The attribute_fd must be a + * handle to an SGX attribute file, e.g. “/dev/sgx/provision". + * + * Failure to explicitly request access to a restricted attribute will cause + * sgx_ioc_enclave_init() to fail. Currently, the only restricted attribute + * is access to the PROVISION_KEY. + * + * Note, access to the EINITTOKEN_KEY is disallowed entirely. + * + * Return: 0 on success, -errno otherwise + */ +static long sgx_ioc_enclave_set_attribute(struct sgx_encl *encl, + void __user *arg) +{ + struct sgx_enclave_set_attribute params; + struct file *attribute_file; + int ret; + + if (copy_from_user(¶ms, arg, sizeof(params))) + return -EFAULT; + + attribute_file = fget(params.attribute_fd); + if (!attribute_file) + return -EINVAL; + + if (attribute_file->f_op != &sgx_provision_fops) { + ret = -EINVAL; + goto out; + } + + encl->allowed_attributes |= SGX_ATTR_PROVISIONKEY; + ret = 0; + +out: + fput(attribute_file); + return ret; +} long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { @@ -601,6 +645,9 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) case SGX_IOC_ENCLAVE_INIT: ret = sgx_ioc_enclave_init(encl, (void __user *)arg); break; + case SGX_IOC_ENCLAVE_SET_ATTRIBUTE: + ret = sgx_ioc_enclave_set_attribute(encl, (void __user *)arg); + break; default: ret = -ENOIOCTLCMD; break;