kyverno/charts/kyverno-policies/templates/default/disallow-host-namespaces.yaml

{{- $name := "disallow-host-namespaces" }}
{{- if eq (include "kyverno-policies.podSecurityBaseline" (merge (dict "name" $name) .)) "true" }}
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: {{ $name }}
  annotations:
    policies.kyverno.io/category: Pod Security Standards (Default)
    {{- if .Values.podSecuritySeverity }}
    policies.kyverno.io/severity: {{ .Values.podSecuritySeverity | quote }}
    {{- end }}
    policies.kyverno.io/description: >-
      Host namespaces (Process ID namespace, Inter-Process Communication namespace, and
      network namespace) allow access to shared information and can be used to elevate
      privileges. Pods should not be allowed access to host namespaces.
  labels: {{ include "kyverno-policies.labels" . | nindent 4 }}
    app: kyverno
spec:
  validationFailureAction: {{ .Values.validationFailureAction }}
  background: true
  rules:
  - name: host-namespaces
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: >-
        Sharing the host namespaces is disallowed. The fields spec.hostNetwork,
        spec.hostIPC, and spec.hostPID must not be set to true.
      pattern:
        spec:
          =(hostPID): "false"
          =(hostIPC): "false"
          =(hostNetwork): "false"
{{- end -}}