Cis Ocp Vm V100 1 1

CIS 1.1 — Restrict GPU and USB pass through to approved devices

Profile Applicability

• Level 1

Description

The ability to pass through devices provides the capability to offload tasks from the CPU to the device itself.

Rationale

Restricting passthrough to approved devices reduces the risk of unauthorized or unintended data sharing/transmission introduced by allowing GPU and USB connectivity.

Impact

Unauthorized devices will not be passed through, and therefore not be available to workloads.

Audit Procedure

List the host devices available to virtualization workloads and verify the host devices returned are necessary for workload execution.

$ oc get hyperconverged kubevirt-hyperconverged -n openshift-cnv -ojsonpath='{.spec.permittedHostDevices}'

Example output structure:

{
  "mediatedDevices": [
    {
      "mdevNameSelector": "DEVICE_A",
      "resourceName": "vendor.com/DEVICE_A"
    }
  ],
  "pciHostDevices": [
    {
      "externalResourceProvider": true,
      "pciDeviceSelector": "XXX:YYY",
      "resourceName": "vendor.com/DEVICE_B"
    },
    {
      "pciDeviceSelector": "NNN:MMM",
      "resourceName": "vendor.com/DEVICE_C"
    }
  ],
  "usbHostDevices": [
    {
      "resourceName": "kubevirt.io/storage",
      "selectors": [
        {
          "product": "0001",
          "vendor": "46f4"
        }
      ]
    }
  ]
}

Remediation

Enforcing limitations to the passthrough of approved devices protects against the introduction of a malicious or unknown device to the system. The system administrator can remove the unwanted devices by patching the HCO object.

If the first PCI device (the DEVICE_A at index 0) should not be permitted to be passed through to a VM, here's how to remove it:

$ oc patch hyperconverged kubevirt-hyperconverged -n openshift-cnv --type='json' -p='[
    {"op": "remove", "path": "/spec/permittedHostDevices/pciHostDevices/0"},
]'

To remove all permitted devices, use the following:

$ oc patch hyperconverged kubevirt-hyperconverged -n openshift-cnv --type='json' -p='[
    {"op": "remove", "path": "/spec/permittedHostDevices"},
]'

Default Value

By default, OpenShift Virtualization doesn't configure any pass through devices. The result of the command should be empty.

References

• CIS Redhat OpenShift Virtual Machine Extension Benchmark v1.0.0, Section 1.1

CIS Controls

MITRE ATT&CK Mappings

Profile

• Level 1 - OpenShift Virtualization