Affected versions: Oracle Linux 8

πŸ“– ~4 min read  β€’  Source: Oracle Bug 29478124

Table of contents
  1. Symptom & Impact
  2. Environment & Reproduction
  3. Root Cause Analysis
  4. Quick Triage
  5. Step-by-Step Diagnosis
  6. Solution – Primary Fix
  7. Solution – Alternative Approaches
  8. Verification & Acceptance Criteria
  9. Rollback Plan
  10. Prevention & Hardening
  11. Related Errors & Cross-Refs
  12. References & Further Reading

Symptom & Impact

On Oracle Linux 8 systems, Oracle Bug 29478124 reports the behaviour described in the title: restarting firewalld service results in ssh connection timeout. The condition surfaces during install, boot, or normal operation depending on the affected subsystem. Operators see failed systemctl status output, abnormal entries in journalctl -xe, and β€” where the package is part of the serving path β€” degraded availability. On Oracle Linux 8, impact ranges from a single service restart loop to wider production incidents depending on host role and the criticality of Restarting.

Environment & Reproduction

Reproduction targets Oracle Linux 8 running either the Red Hat Compatible Kernel or the Unbreakable Enterprise Kernel. Confirm release with cat /etc/oracle-release and kernel with uname -r. Trigger the workflow that exposes Restarting firewalld service results in SSH connection timeout while collecting journalctl -b, dnf history, and rpm -qa output for correlation against Oracle Bug 29478124.

Root Cause Analysis

Root cause is tracked in the Oracle Linux release notes (Oracle Bug 29478124). The defect lives in a specific kernel, firmware, or userspace component shipped with the GA channel and Oracle has documented either a fix in a later errata or a supported workaround. Correlate journalctl --since timestamps with dnf history and ausearch -m AVC entries to isolate the originating change. On Oracle Linux 8, modular streams, UEK kernel variants, and OEL-specific errata can each shift the package set used by the failure path.

Quick Triage

Quick triage: run systemctl status Restarting, journalctl -u Restarting -n 200, firewall-cmd --list-all, getenforce, dnf check, and rpm -Va. If SELinux is enforcing, capture ausearch -m AVC -ts recent to surface denials linked to Restarting firewalld service results in SSH connection timeout.

Step-by-Step Diagnosis

1) Confirm the symptom with systemctl --failed. 2) Inspect logs: journalctl -xe and journalctl -u Restarting. 3) Validate firewall: firewall-cmd --list-all-zones. 4) Check SELinux denials: ausearch -m AVC,USER_AVC -ts today. 5) Verify package integrity: dnf check and rpm -V Restarting. 6) Correlate findings with dnf history, /var/log/dnf.log and Oracle Bug 29478124 to pin the change that introduced Restarting firewalld service results in SSH connection timeout.

Solution – Primary Fix

Primary fix for Restarting firewalld service results in SSH connection timeout: apply the corrective dnf transaction described in Oracle Bug 29478124, reload the affected systemd unit, and reconcile firewalld and SELinux state. Typical commands: sudo dnf -y update, sudo dnf -y upgrade --refresh, sudo systemctl daemon-reload, sudo reboot (only if the advisory says a reboot is required). Validate immediately with systemctl is-active Restarting.

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Solution – Alternative Approaches

Alternatives include rolling back the offending transaction with sudo dnf history undo <id>, pinning the package via dnf versionlock, switching the firewall backend between nftables and iptables in /etc/firewalld/firewalld.conf, or temporarily setting SELinux permissive (setenforce 0) to confirm policy is the cause before authoring a custom module with audit2allow. For Oracle Linux specifically, Ksplice live patching may close the gap without reboot when the advisory has Ksplice coverage.

Verification & Acceptance Criteria

Acceptance: uname -r && cat /etc/oracle-release shows the expected fixed version, systemctl is-active Restarting returns active, journalctl -u Restarting --since "5 minutes ago" shows no errors, firewall-cmd --list-services includes the required services, getenforce reports the intended mode, and the original reproduction steps for Restarting firewalld service results in SSH connection timeout no longer trigger the failure across two consecutive runs.

Rollback Plan

Capture state with dnf history list and rpm -qa > /root/rpm-pre.txt before any change. To revert, run sudo dnf history undo <id>, restore /etc backups, and reload systemctl daemon-reload. For SELinux modules, remove with sudo semodule -r <module>. Reboot if the kernel or initramfs was changed and re-verify symptoms.

Prevention & Hardening

Prevent recurrence with dnf-automatic security updates, needs-restarting -r checks, immutable systemd drop-ins under /etc/systemd/system/<unit>.d/, version-locked firewalld zones, and audit rules in /etc/audit/rules.d/. Apply CIS Oracle Linux 8 hardening, subscribe to the Oracle Linux errata mailing list, and monitor file integrity with aide --check. Where supported, enable Oracle Ksplice so future advisories like this can be remediated live without reboot.

Related issues that commonly surface alongside Restarting firewalld service results in SSH connection timeout: dnf transaction lock contention, systemd unit ordering cycles, SELinux AVC bursts, firewalld zone drift, and kernel taint flags shown by cat /proc/sys/kernel/tainted. See sibling common-problem articles in this Oracle Linux 8 series for adjacent failure modes.

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References & Further Reading

Primary reference: Oracle Bug 29478124. Supporting docs: Oracle Linux 8 Administrators Guide, Red Hat Enterprise Linux documentation (upstream), man dnf, man systemctl, man firewall-cmd, man semanage, man journalctl, the Oracle Linux yum server changelog, and the Oracle Ksplice known-fixes feed. Review /usr/share/doc/ package documentation for the components implicated in Restarting firewalld service results in SSH connection timeout.