Vulnerability Discussion

To ensure RHCOS has a sufficient storage capacity in which to write the audit logs, operating systems need to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is performed during initial installation of the operating system.

Check

Verify RHCOS allocates audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility.

Check the size of the partition to which audit records are written (with the example being /var/log/audit/) by executing the following:

for node in $(oc get node -oname); do oc debug $node -- chroot /host /bin/bash -c 'echo -n "$HOSTNAME "; df -h /var/log/audit/' 2>/dev/null; done

Filesystem Size Used Avail Use% Mounted on
/dev/sdb4 1.0T 27G 998G 3% /var

If the audit record partition is not allocated for sufficient storage capacity, this is a finding.

Note: The partition size needed to capture a week of audit records is based on the activity level of the system and the total storage capacity available. Typically, 10.0 GB of storage space for audit records should be sufficient. If the partition used is not exclusively for audit logs, then determine the amount of additional space needed to support the partition reserving enough space for audit logs.

Fix

Reinstall the cluster, generating custom ignition configs to allocate audit record storage capacity.

1. Generate manifest files for the cluster by executing the following:

openshift-install create manifests --dir

2. Create a Butane config that configures additional partition by executing the following:

variant: openshift
version: 4.9.0
metadata:
labels:
machineconfiguration.openshift.io/role: worker
name: 98-var-partition
storage:
disks:
- device: /dev/
partitions:
- label: var
start_mib:
size_mib:
filesystems:
- device: /dev/disk/by-partlabel/var
path: /var
format: xfs
mount_options: [rw, nodev, nosuid, noexec,...]
with_mount_unit: true

3. Create a manifest from the Butane config by executing the following:

butane /98-var-partition.bu -o /openshift/98-var-partition.yaml

4. Create the ignition config files by executing the following:

openshift-install create ignition-configs --dir