Security policies

Learn about OpenShift Virtualization security and authorization.

Key points

OpenShift Virtualization adheres to the restricted Kubernetes pod security standards profile, which aims to enforce the current best practices for pod security.
Virtual machine (VM) workloads run as unprivileged pods.
Security context constraints (SCCs) are defined for the kubevirt-controller service account.
TLS certificates for OpenShift Virtualization components are renewed and rotated automatically.

About workload security

By default, virtual machine (VM) workloads do not run with root privileges in OpenShift Virtualization, and there are no supported OpenShift Virtualization features that require root privileges.

For each VM, a virt-launcher pod runs an instance of libvirt in session mode to manage the VM process. In session mode, the libvirt daemon runs as a non-root user account and only permits connections from clients that are running under the same user identifier (UID). Therefore, VMs run as unprivileged pods, adhering to the security principle of least privilege.

TLS certificates

TLS certificates for OpenShift Virtualization components are renewed and rotated automatically. You are not required to refresh them manually.

Automatic renewal schedules

TLS certificates are automatically deleted and replaced according to the following schedule:

KubeVirt certificates are renewed daily.
Containerized Data Importer controller (CDI) certificates are renewed every 15 days.
MAC pool certificates are renewed every year.

Automatic TLS certificate rotation does not disrupt any operations. For example, the following operations continue to function without any disruption:

Migrations
Image uploads
VNC and console connections

Authorization

OpenShift Virtualization uses role-based access control (RBAC) to define permissions for human users and service accounts. The permissions defined for service accounts control the actions that OpenShift Virtualization components can perform.

You can also use RBAC roles to manage user access to virtualization features. For example, an administrator can create an RBAC role that provides the permissions required to launch a virtual machine. The administrator can then restrict access by binding the role to specific users.

Default cluster roles for OpenShift Virtualization

By using cluster role aggregation, OpenShift Virtualization extends the default OpenShift Container Platform cluster roles to include permissions for accessing virtualization objects. Roles unique to OpenShift Virtualization are not aggregated with OpenShift Container Platform roles.

Table 1. OpenShift Virtualization cluster roles
Default cluster role	OpenShift Virtualization cluster role	OpenShift Virtualization cluster role description
`view`	`kubevirt.io:view`	A user that can view all OpenShift Virtualization resources in the cluster but cannot create, delete, modify, or access them. For example, the user can see that a virtual machine (VM) is running but cannot shut it down or gain access to its console.
`edit`	`kubevirt.io:edit`	A user that can modify all OpenShift Virtualization resources in the cluster. For example, the user can create VMs, access VM consoles, and delete VMs.
`admin`	`kubevirt.io:admin`	A user that has full permissions to all OpenShift Virtualization resources, including the ability to delete collections of resources. The user can also view and modify the OpenShift Virtualization runtime configuration, which is located in the `HyperConverged` custom resource in the `openshift-cnv` namespace.
`N/A`	`kubevirt.io:migrate`	A user that can create, delete, and update VM live migration requests, which are represented by namespaced `VirtualMachineInstanceMigration` (VMIM) objects. This role is specific to OpenShift Virtualization.

RBAC roles for storage features in OpenShift Virtualization

The following permissions are granted to the Containerized Data Importer (CDI), including the cdi-operator and cdi-controller service accounts.

Cluster-wide RBAC roles

Table 2. Aggregated cluster roles for the `cdi.kubevirt.io` API group
CDI cluster role	Resources	Verbs
`cdi.kubevirt.io:admin`	`datavolumes`, `uploadtokenrequests`	`*` (all)
`cdi.kubevirt.io:admin`	`datavolumes/source`	`create`
`cdi.kubevirt.io:edit`	`datavolumes`, `uploadtokenrequests`	`*`
`cdi.kubevirt.io:edit`	`datavolumes/source`	`create`
`cdi.kubevirt.io:view`	`cdiconfigs`, `dataimportcrons`, `datasources`, `datavolumes`, `objecttransfers`, `storageprofiles`, `volumeimportsources`, `volumeuploadsources`, `volumeclonesources`	`get`, `list`, `watch`
`cdi.kubevirt.io:view`	`datavolumes/source`	`create`
`cdi.kubevirt.io:config-reader`	`cdiconfigs`, `storageprofiles`	`get`, `list`, `watch`

Table 3. Cluster-wide roles for the `cdi-operator` service account
API group	Resources	Verbs
`rbac.authorization.k8s.io`	`clusterrolebindings`, `clusterroles`	`get`, `list`, `watch`, `create`, `update`, `delete`
`security.openshift.io`	`securitycontextconstraints`	`get`, `list`, `watch`, `update`, `create`
`apiextensions.k8s.io`	`customresourcedefinitions`, `customresourcedefinitions/status`	`get`, `list`, `watch`, `create`, `update`, `delete`
`cdi.kubevirt.io`	`*`	`*`
`upload.cdi.kubevirt.io`	`*`	`*`
`admissionregistration.k8s.io`	`validatingwebhookconfigurations`, `mutatingwebhookconfigurations`	`create`, `list`, `watch`
`admissionregistration.k8s.io`	`validatingwebhookconfigurations` Allow list: `cdi-api-dataimportcron-validate, cdi-api-populator-validate, cdi-api-datavolume-validate, cdi-api-validate, objecttransfer-api-validate`	`get`, `update`, `delete`
`admissionregistration.k8s.io`	`mutatingwebhookconfigurations` Allow list: `cdi-api-datavolume-mutate`	`get`, `update`, `delete`
`apiregistration.k8s.io`	`apiservices`	`get`, `list`, `watch`, `create`, `update`, `delete`

Table 4. Cluster-wide roles for the `cdi-controller` service account
API group	Resources	Verbs
`""` (core)	`events`	`create`, `patch`
`""` (core)	`persistentvolumeclaims`	`get`, `list`, `watch`, `create`, `update`, `delete`, `deletecollection`, `patch`
`""` (core)	`persistentvolumes`	`get`, `list`, `watch`, `update`
`""` (core)	`persistentvolumeclaims/finalizers`, `pods/finalizers`	`update`
`""` (core)	`pods`, `services`	`get`, `list`, `watch`, `create`, `delete`
`""` (core)	`configmaps`	`get`, `create`
`storage.k8s.io`	`storageclasses`, `csidrivers`	`get`, `list`, `watch`
`config.openshift.io`	`proxies`	`get`, `list`, `watch`
`cdi.kubevirt.io`	`*`	`*`
`snapshot.storage.k8s.io`	`volumesnapshots`, `volumesnapshotclasses`, `volumesnapshotcontents`	`get`, `list`, `watch`, `create`, `delete`
`snapshot.storage.k8s.io`	`volumesnapshots`	`update`, `deletecollection`
`apiextensions.k8s.io`	`customresourcedefinitions`	`get`, `list`, `watch`
`scheduling.k8s.io`	`priorityclasses`	`get`, `list`, `watch`
`image.openshift.io`	`imagestreams`	`get`, `list`, `watch`
`""` (core)	`secrets`	`create`
`kubevirt.io`	`virtualmachines/finalizers`	`update`

Namespaced RBAC roles

Table 5. Namespaced roles for the `cdi-operator` service account
API group	Resources	Verbs
`rbac.authorization.k8s.io`	`rolebindings`, `roles`	`get`, `list`, `watch`, `create`, `update`, `delete`
`""` (core)	`serviceaccounts`, `configmaps`, `events`, `secrets`, `services`	`get`, `list`, `watch`, `create`, `update`, `patch`, `delete`
`apps`	`deployments`, `deployments/finalizers`	`get`, `list`, `watch`, `create`, `update`, `delete`
`route.openshift.io`	`routes`, `routes/custom-host`	`get`, `list`, `watch`, `create`, `update`
`config.openshift.io`	`proxies`	`get`, `list`, `watch`
`monitoring.coreos.com`	`servicemonitors`, `prometheusrules`	`get`, `list`, `watch`, `create`, `delete`, `update`, `patch`
`coordination.k8s.io`	`leases`	`get`, `create`, `update`

Table 6. Namespaced roles for the `cdi-controller` service account
API group	Resources	Verbs
`""` (core)	`configmaps`	`get`, `list`, `watch`, `create`, `update`, `delete`
`""` (core)	`secrets`	`get`, `list`, `watch`
`batch`	`cronjobs`	`get`, `list`, `watch`, `create`, `update`, `delete`
`batch`	`jobs`	`create`, `delete`, `list`, `watch`
`coordination.k8s.io`	`leases`	`get`, `create`, `update`
`networking.k8s.io`	`ingresses`	`get`, `list`, `watch`
`route.openshift.io`	`routes`	`get`, `list`, `watch`

Additional SCCs and permissions for the kubevirt-controller service account

Security context constraints (SCCs) control permissions for pods. These permissions include actions that a pod, a collection of containers, can perform and what resources it can access. You can use SCCs to define a set of conditions that a pod must run with to be accepted into the system.

The virt-controller is a cluster controller that creates the virt-launcher pods for virtual machines in the cluster.

Note

By default, virt-launcher pods run with the default service account in the namespace. If your compliance controls require a unique service account, assign one to the VM. The setting applies to the VirtualMachineInstance object and the virt-launcher pod.

The kubevirt-controller service account is granted additional SCCs and Linux capabilities so that it can create virt-launcher pods with the appropriate permissions. These extended permissions allow virtual machines to use OpenShift Virtualization features that are beyond the scope of typical pods.

The kubevirt-controller service account is granted the following SCCs:

scc.AllowHostDirVolumePlugin = true

This allows virtual machines to use the hostpath volume plugin.

scc.AllowPrivilegedContainer = false

This ensures the virt-launcher pod is not run as a privileged container.

scc.AllowedCapabilities = []corev1.Capability{"SYS_NICE", "NET_BIND_SERVICE"}

SYS_NICE allows setting the CPU affinity.
NET_BIND_SERVICE allows DHCP and Slirp operations.

Viewing the SCC and RBAC definitions for the kubevirt-controller

You can view the SecurityContextConstraints definition for the kubevirt-controller by using the oc tool:

$ oc get scc kubevirt-controller -o yaml

You can view the RBAC definition for the kubevirt-controller clusterrole by using the oc tool:

$ oc get clusterrole kubevirt-controller -o yaml