From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DB04C433F7 for ; Thu, 23 Jul 2020 17:19:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0A7722B40 for ; Thu, 23 Jul 2020 17:19:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730016AbgGWRTB (ORCPT ); Thu, 23 Jul 2020 13:19:01 -0400 Received: from mga09.intel.com ([134.134.136.24]:65333 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729811AbgGWRS5 (ORCPT ); Thu, 23 Jul 2020 13:18:57 -0400 IronPort-SDR: 7cJu+3lJNUBOi/ud4fi2WXDACCRFX/rqeHP3sGD+f0fl3rH88c6D3yL2MoUV+h5qUXnrsDBav7 BY1LI9U793fA== X-IronPort-AV: E=McAfee;i="6000,8403,9691"; a="151880963" X-IronPort-AV: E=Sophos;i="5.75,387,1589266800"; d="scan'208";a="151880963" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jul 2020 10:18:55 -0700 IronPort-SDR: 8ssdZmrgyUQZslE6gdIt9RKxi2biCkXCNV+naNyVJtk5qnBzjDZkDw9qV8iinQ46gnuyyKQpRP KDs5XGOUnI8Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,387,1589266800"; d="scan'208";a="462933858" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga005.jf.intel.com with ESMTP; 23 Jul 2020 10:18:55 -0700 From: Jacob Pan To: iommu@lists.linux-foundation.org, LKML , Joerg Roedel , Alex Williamson Cc: "Lu Baolu" , David Woodhouse , Yi Liu , "Tian, Kevin" , Raj Ashok , "Christoph Hellwig" , Jean-Philippe Brucker , Eric Auger , Jonathan Corbet , Jacob Pan Subject: [PATCH v6 5/6] iommu/uapi: Handle data and argsz filled by users Date: Thu, 23 Jul 2020 10:25:39 -0700 Message-Id: <1595525140-23899-6-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1595525140-23899-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1595525140-23899-1-git-send-email-jacob.jun.pan@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org IOMMU user APIs are responsible for processing user data. This patch changes the interface such that user pointers can be passed into IOMMU code directly. Separate kernel APIs without user pointers are introduced for in-kernel users of the UAPI functionality. IOMMU UAPI data has a user filled argsz field which indicates the data length of the structure. User data is not trusted, argsz must be validated based on the current kernel data size, mandatory data size, and feature flags. User data may also be extended, resulting in possible argsz increase. Backward compatibility is ensured based on size and flags (or the functional equivalent fields) checking. This patch adds sanity checks in the IOMMU layer. In addition to argsz, reserved/unused fields in padding, flags, and version are also checked. Details are documented in Documentation/userspace-api/iommu.rst Signed-off-by: Liu Yi L Signed-off-by: Jacob Pan --- drivers/iommu/iommu.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++-- include/linux/iommu.h | 28 ++++--- 2 files changed, 213 insertions(+), 17 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3a913ce94a3d..1ce2a61058c6 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1950,33 +1950,219 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) } EXPORT_SYMBOL_GPL(iommu_attach_device); +/* + * Check flags and other user provided data for valid combinations. We also + * make sure no reserved fields or unused flags are set. This is to ensure + * not breaking userspace in the future when these fields or flags are used. + */ +static int iommu_check_cache_invl_data(struct iommu_cache_invalidate_info *info) +{ + u32 mask; + int i; + + if (info->version != IOMMU_CACHE_INVALIDATE_INFO_VERSION_1) + return -EINVAL; + + mask = (1 << IOMMU_CACHE_INV_TYPE_NR) - 1; + if (info->cache & ~mask) + return -EINVAL; + + if (info->granularity >= IOMMU_INV_GRANU_NR) + return -EINVAL; + + switch (info->granularity) { + case IOMMU_INV_GRANU_ADDR: + if (info->cache & IOMMU_CACHE_INV_TYPE_PASID) + return -EINVAL; + + mask = IOMMU_INV_ADDR_FLAGS_PASID | + IOMMU_INV_ADDR_FLAGS_ARCHID | + IOMMU_INV_ADDR_FLAGS_LEAF; + + if (info->granu.addr_info.flags & ~mask) + return -EINVAL; + break; + case IOMMU_INV_GRANU_PASID: + mask = IOMMU_INV_PASID_FLAGS_PASID | + IOMMU_INV_PASID_FLAGS_ARCHID; + if (info->granu.pasid_info.flags & ~mask) + return -EINVAL; + + break; + case IOMMU_INV_GRANU_DOMAIN: + if (info->cache & IOMMU_CACHE_INV_TYPE_DEV_IOTLB) + return -EINVAL; + break; + default: + return -EINVAL; + } + + /* Check reserved padding fields */ + for (i = 0; i < 6; i++) { + if (info->padding[i]) + return -EINVAL; + } + + return 0; +} + int iommu_uapi_cache_invalidate(struct iommu_domain *domain, struct device *dev, - struct iommu_cache_invalidate_info *inv_info) + void __user *uinfo) { + struct iommu_cache_invalidate_info inv_info = { 0 }; + u32 minsz; + int ret = 0; + if (unlikely(!domain->ops->cache_invalidate)) return -ENODEV; - return domain->ops->cache_invalidate(domain, dev, inv_info); + /* + * No new spaces can be added before the variable sized union, the + * minimum size is the offset to the union. + */ + minsz = offsetof(struct iommu_cache_invalidate_info, granu); + + /* Copy minsz from user to get flags and argsz */ + if (copy_from_user(&inv_info, uinfo, minsz)) + return -EFAULT; + + /* Fields before variable size union is mandatory */ + if (inv_info.argsz < minsz) + return -EINVAL; + + /* PASID and address granu require additional info beyond minsz */ + if (inv_info.argsz == minsz && + ((inv_info.granularity == IOMMU_INV_GRANU_PASID) || + (inv_info.granularity == IOMMU_INV_GRANU_ADDR))) + return -EINVAL; + + if (inv_info.granularity == IOMMU_INV_GRANU_PASID && + inv_info.argsz < offsetofend(struct iommu_cache_invalidate_info, granu.pasid_info)) + return -EINVAL; + + if (inv_info.granularity == IOMMU_INV_GRANU_ADDR && + inv_info.argsz < offsetofend(struct iommu_cache_invalidate_info, granu.addr_info)) + return -EINVAL; + + /* + * User might be using a newer UAPI header which has a larger data + * size, we shall support the existing flags within the current + * size. Copy the remaining user data _after_ minsz but not more + * than the current kernel supported size. + */ + if (copy_from_user((void *)&inv_info + minsz, uinfo + minsz, + min(inv_info.argsz, (u32)sizeof(inv_info)) - minsz)) + return -EFAULT; + + /* Now the argsz is validated, check the content */ + ret = iommu_check_cache_invl_data(&inv_info); + if (ret) + return ret; + + return domain->ops->cache_invalidate(domain, dev, &inv_info); } EXPORT_SYMBOL_GPL(iommu_uapi_cache_invalidate); -int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, - struct device *dev, struct iommu_gpasid_bind_data *data) +static int iommu_check_bind_data(struct iommu_gpasid_bind_data *data) +{ + u32 mask; + int i; + + if (data->version != IOMMU_GPASID_BIND_VERSION_1) + return -EINVAL; + + /* Check all supported format, for now just VT-d */ + mask = IOMMU_PASID_FORMAT_INTEL_VTD; + if (data->format & ~mask) + return -EINVAL; + + /* Check all flags */ + mask = IOMMU_SVA_GPASID_VAL; + if (data->flags & ~mask) + return -EINVAL; + + /* Check reserved padding fields */ + for (i = 0; i < 8; i++) { + if (data->padding[i]) + return -EINVAL; + } + + return 0; +} + +static int iommu_sva_prepare_bind_data(void __user *udata, + struct iommu_gpasid_bind_data *data) { + u32 minsz; + + /* + * No new spaces can be added before the variable sized union, the + * minimum size is the offset to the union. + */ + minsz = offsetof(struct iommu_gpasid_bind_data, vendor); + + /* Copy minsz from user to get flags and argsz */ + if (copy_from_user(data, udata, minsz)) + return -EFAULT; + + /* Fields before variable size union is mandatory */ + if (data->argsz < minsz) + return -EINVAL; + /* + * User might be using a newer UAPI header, we shall let IOMMU vendor + * driver decide on what size it needs. Since the guest PASID bind data + * can be vendor specific, larger argsz could be the result of extension + * for one vendor but it should not affect another vendor. + * Copy the remaining user data _after_ minsz + */ + if (copy_from_user((void *)data + minsz, udata + minsz, + min(data->argsz, (u32)sizeof(*data)) - minsz)) + return -EFAULT; + + return iommu_check_bind_data(data); +} + +int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, struct device *dev, + void __user *udata) +{ + struct iommu_gpasid_bind_data data = { 0 }; + int ret; + if (unlikely(!domain->ops->sva_bind_gpasid)) return -ENODEV; - return domain->ops->sva_bind_gpasid(domain, dev, data); + ret = iommu_sva_prepare_bind_data(udata, &data); + if (ret) + return ret; + + return domain->ops->sva_bind_gpasid(domain, dev, &data); } EXPORT_SYMBOL_GPL(iommu_uapi_sva_bind_gpasid); -int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev, - ioasid_t pasid) +int iommu_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev, + struct iommu_gpasid_bind_data *data) { if (unlikely(!domain->ops->sva_unbind_gpasid)) return -ENODEV; - return domain->ops->sva_unbind_gpasid(dev, pasid); + return domain->ops->sva_unbind_gpasid(dev, data->hpasid); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); + +int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev, + void __user *udata) +{ + struct iommu_gpasid_bind_data data = { 0 }; + int ret; + + if (unlikely(!domain->ops->sva_bind_gpasid)) + return -ENODEV; + + ret = iommu_sva_prepare_bind_data(udata, &data); + if (ret) + return ret; + + return iommu_sva_unbind_gpasid(domain, dev, &data); } EXPORT_SYMBOL_GPL(iommu_uapi_sva_unbind_gpasid); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 2dcc1a33f6dc..4a02c9e09048 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -432,11 +432,14 @@ extern void iommu_detach_device(struct iommu_domain *domain, struct device *dev); extern int iommu_uapi_cache_invalidate(struct iommu_domain *domain, struct device *dev, - struct iommu_cache_invalidate_info *inv_info); + void __user *uinfo); + extern int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, - struct device *dev, struct iommu_gpasid_bind_data *data); + struct device *dev, void __user *udata); extern int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid); + struct device *dev, void __user *udata); +extern int iommu_sva_unbind_gpasid(struct iommu_domain *domain, + struct device *dev, struct iommu_gpasid_bind_data *data); extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); extern struct iommu_domain *iommu_get_dma_domain(struct device *dev); extern int iommu_map(struct iommu_domain *domain, unsigned long iova, @@ -1054,22 +1057,29 @@ static inline int iommu_sva_get_pasid(struct iommu_sva *handle) return IOMMU_PASID_INVALID; } -static inline int iommu_uapi_cache_invalidate(struct iommu_domain *domain, - struct device *dev, - struct iommu_cache_invalidate_info *inv_info) +static inline int +iommu_uapi_cache_invalidate(struct iommu_domain *domain, + struct device *dev, + struct iommu_cache_invalidate_info *inv_info) { return -ENODEV; } static inline int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, - struct device *dev, - struct iommu_gpasid_bind_data *data) + struct device *dev, void __user *udata) { return -ENODEV; } static inline int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, - struct device *dev, int pasid) + struct device *dev, void __user *udata) +{ + return -ENODEV; +} + +static inline int iommu_sva_unbind_gpasid(struct iommu_domain *domain, + struct device *dev, + struct iommu_gpasid_bind_data *data) { return -ENODEV; } -- 2.7.4