Cis Ocp Vm V100 3 3

CIS 3.3 — Ensure errorPolicy is not set to ignore

Profile Applicability

• Level 1

Description

Error policies for disks control how Input/Output (IO) errors are handled. If a read or write operation fails on the storage, an IO error occurs. Setting the error policy to ignore is not recommended because it makes it difficult to determine the root cause of any IO issues, which can lead to data loss if the data is not correctly written to the disk.

Rationale

Certain applications, such as Windows Shared Cluster Filesystem, require a different behavior than the default error policy setting. IO errors need to be reported to the guest Operating System by setting the errorPolicy to report.

Impact

Emergency or maintenance activities may require reducing log generation by temporarily ignoring the IO errors. This may be accomplished by setting the errorPolicy to ignore.

Audit Procedure

Verify that no virtual machines are using the errorPolicy set to ignore:

$ oc get vm -ojson -A | jq '.items[] | select(.spec.template.spec.domain.devices.disks[].errorPolicy == "ignore")| .metadata.namespace + "/" + .metadata.name'

Remediation

Remove the errorPolicy or set it to stop(default value) or report (suggested option for Windows Shared Cluster Filesystem). For example, to remove the errorPolicy flag on the first disk (index 0) of a given VM, this command can be used:

$ oc patch vm <vm-name> --type='json' -p='[
    {"op": "remove", "path": "/spec/template/spec/domain/devices/disks/0/errorPolicy"},
]'

To set an errorPolicy flag to stop on every disk, this (experimental) command can be used:

$ oc get vm <vm-name> -o json | jq '.spec.template.spec.domain.devices.disks[] += {"errorPolicy":"stop"}' | oc apply -f -

Default Value

By default the errorPolicy is not set on any disk and the default value is stop. The audit procedure should return an empty list.

References

None listed in the PDF.

CIS Controls

MITRE ATT&CK Mappings

Profile

• Level 1 - OpenShift Virtualization