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authorGiovanni Cabiddu <giovanni.cabiddu@intel.com>2020-07-27 13:43:40 -0600
committerAlex Williamson <alex.williamson@redhat.com>2020-07-27 13:43:40 -0600
commit1f97970e6c8e60349b045599f4525608db895009 (patch)
tree254dd45f52af7cf395a6214c0cae77325fb16399 /drivers/vfio/pci/vfio_pci.c
parent8b7beaf9f185249f29912b5e2d7bc4147c5c2a6a (diff)
vfio/pci: Add device denylist
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 <giovanni.cabiddu@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Fiona Trahe <fiona.trahe@intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/pci/vfio_pci.c')
-rw-r--r--drivers/vfio/pci/vfio_pci.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index dabca0450e6d..f368a3993ac1 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 allows 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
@@ -1856,6 +1883,9 @@ 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;
@@ -2345,6 +2375,9 @@ static int __init vfio_pci_init(void)
vfio_pci_fill_ids();
+ if (disable_denylist)
+ pr_warn("device denylist disabled.\n");
+
return 0;
out_driver: