CNF-23514: RAN Hardening (5.0) - Auditd Configuration (M9)

[sebrandon1]

Summary

Adds MachineConfig to deploy hardened auditd configuration on both master and worker nodes.

This addresses MEDIUM severity findings from the ACSC Essential Eight compliance profile — hardening the auditd service configuration to ensure proper audit logging settings (hostname identification, disk-full behavior, queue depth).

Remediation Group

• M9: Auditd Configuration

Files

• 75-auditd-configuration-master.yaml
• 75-auditd-configuration-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/<node> -- chroot /host cat /etc/audit/auditd.conf
# Expected: hardened auditd configuration

Jira

• Epic: CNF-22573 (RAN Hardening for 5.0)

OCP 5.0 Verification (2026-06-22)

Cluster: cnfdt16 — OCP 5.0.0-0.nightly-2026-06-18-000016, RHCOS 10.2

Finding: Hardening still needed. Stock RHCOS 10 auditd.conf has several compliance-relevant differences.

Setting	RHCOS 10 Default	Hardened (M9)	Impact
name_format	NONE	hostname	Identify audit source in centralized logs
space_left	75	100	Earlier warning when disk space low
admin_space_left_action	SUSPEND	syslog	Keep logging vs silently stop
disk_full_action	SUSPEND	syslog	Keep logging vs silently stop
disk_error_action	SUSPEND	syslog	Keep logging vs silently stop
q_depth	2000	400	Compliance-recommended queue depth
max_log_file	8	6	Compliance-recommended max log size (MB)

The critical change is the *_action settings: RHCOS 10 defaults to SUSPEND which silently stops audit logging when disk issues occur. The hardened config changes these to syslog so audit events are still captured via syslog.

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• telco-ran/configuration/kube-compare-reference/informational/hardening/75-auditd-configuration-master.yaml
• telco-ran/configuration/kube-compare-reference/informational/hardening/75-auditd-configuration-worker.yaml

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[openshift-ci-robot]

@sebrandon1: This pull request references CNF-23514 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

Details

In response to this:

Summary

Adds MachineConfig to deploy hardened auditd configuration on both master and worker nodes.

This addresses MEDIUM severity findings from the ACSC Essential Eight compliance profile — hardening the auditd service configuration to ensure proper audit logging settings (hostname identification, disk-full behavior, queue depth).

Remediation Group

• M9: Auditd Configuration

Files

• 75-auditd-configuration-master.yaml
• 75-auditd-configuration-worker.yaml

Verification

After applying to a cluster, verify with:

oc debug node/<node> -- chroot /host cat /etc/audit/auditd.conf
# Expected: hardened auditd configuration

Jira

• Epic: CNF-22573 (RAN Hardening for 5.0)

OCP 5.0 Verification (2026-06-22)

Cluster: cnfdt16 — OCP 5.0.0-0.nightly-2026-06-18-000016, RHCOS 10.2

Finding: Hardening still needed. Stock RHCOS 10 auditd.conf has several compliance-relevant differences.

Setting	RHCOS 10 Default	Hardened (M9)	Impact
name_format	NONE	hostname	Identify audit source in centralized logs
space_left	75	100	Earlier warning when disk space low
admin_space_left_action	SUSPEND	syslog	Keep logging vs silently stop
disk_full_action	SUSPEND	syslog	Keep logging vs silently stop
disk_error_action	SUSPEND	syslog	Keep logging vs silently stop
q_depth	2000	400	Compliance-recommended queue depth
max_log_file	8	6	Compliance-recommended max log size (MB)

The critical change is the *_action settings: RHCOS 10 defaults to SUSPEND which silently stops audit logging when disk issues occur. The hardened config changes these to syslog so audit events are still captured via syslog.

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