From patchwork Thu Jul 23 21:47:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Cabiddu, Giovanni" X-Patchwork-Id: 11681671 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 B0945722 for ; Thu, 23 Jul 2020 21:47:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0CE720825 for ; Thu, 23 Jul 2020 21:47:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728008AbgGWVrh (ORCPT ); Thu, 23 Jul 2020 17:47:37 -0400 Received: from mga04.intel.com ([192.55.52.120]:44379 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728027AbgGWVrd (ORCPT ); Thu, 23 Jul 2020 17:47:33 -0400 IronPort-SDR: OjrFRI8yCtlvV7BSCFEYIC8bZy6GiyOpGCemU0RbCjjV4DBPKFOZWY9Y3TSwHWsca7w4NDWdgu RQHn+IyPzfkA== X-IronPort-AV: E=McAfee;i="6000,8403,9691"; a="148119987" X-IronPort-AV: E=Sophos;i="5.75,388,1589266800"; d="scan'208";a="148119987" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jul 2020 14:47:32 -0700 IronPort-SDR: 1dwkdRzY8w5c6dtMzLClP43u/CEnoOunWElU8Ez6fkiir63mDeNeVzprdP6cmaR28fY7TUxd3o hc+T6WxEVXRg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,388,1589266800"; d="scan'208";a="311183983" Received: from silpixa00400314.ir.intel.com (HELO silpixa00400314.ger.corp.intel.com) ([10.237.222.51]) by fmsmga004.fm.intel.com with ESMTP; 23 Jul 2020 14:47:28 -0700 From: Giovanni Cabiddu To: alex.williamson@redhat.com, herbert@gondor.apana.org.au Cc: cohuck@redhat.com, nhorman@redhat.com, vdronov@redhat.com, bhelgaas@google.com, mark.a.chambers@intel.com, gordon.mcfadden@intel.com, ahsan.atta@intel.com, fiona.trahe@intel.com, qat-linux@intel.com, kvm@vger.kernel.org, linux-crypto@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Giovanni Cabiddu Subject: [PATCH v3 2/5] vfio/pci: Add device denylist Date: Thu, 23 Jul 2020 22:47:02 +0100 Message-Id: <20200723214705.5399-3-giovanni.cabiddu@intel.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200723214705.5399-1-giovanni.cabiddu@intel.com> References: <20200723214705.5399-1-giovanni.cabiddu@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add denylist of devices that by default are not probed by vfio-pci. Devices in this list may be susceptible to untrusted application, even if the IOMMU is enabled. To be accessed via vfio-pci, the user has to explicitly disable the denylist. The denylist can be disabled via the module parameter disable_denylist. Signed-off-by: Giovanni Cabiddu --- drivers/vfio/pci/vfio_pci.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 7c0779018b1b..673f53c4798e 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -60,6 +60,10 @@ module_param(enable_sriov, bool, 0644); MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration. Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF."); #endif +static bool disable_denylist; +module_param(disable_denylist, bool, 0444); +MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling the denylist prevents binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users."); + static inline bool vfio_vga_disabled(void) { #ifdef CONFIG_VFIO_PCI_VGA @@ -69,6 +73,29 @@ static inline bool vfio_vga_disabled(void) #endif } +static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev) +{ + return false; +} + +static bool vfio_pci_is_denylisted(struct pci_dev *pdev) +{ + if (!vfio_pci_dev_in_denylist(pdev)) + return false; + + if (disable_denylist) { + pci_warn(pdev, + "device denylist disabled - allowing device %04x:%04x.\n", + pdev->vendor, pdev->device); + return false; + } + + pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n", + pdev->vendor, pdev->device); + + return true; +} + /* * Our VGA arbiter participation is limited since we don't know anything * about the device itself. However, if the device is the only VGA device @@ -1847,6 +1874,9 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) struct iommu_group *group; int ret; + if (vfio_pci_is_denylisted(pdev)) + return -EINVAL; + if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL) return -EINVAL; @@ -2336,6 +2366,9 @@ static int __init vfio_pci_init(void) vfio_pci_fill_ids(); + if (disable_denylist) + pr_warn("device denylist disabled.\n"); + return 0; out_driver: