Bench on comet-beacon-54 proved every command-socket route is blocked for the
hardened agent: chronyd's unix socket is owner-write-only (0755, so even a
chrony-group member can't connect), and STIG closes the UDP command port
(cmdport 0). Rather than re-open a port or expose chrony's privileged socket,
enable chronyd's tracking log and have the agent READ it — no port, no socket,
no group, no SELinux domain transition, full hardening intact.
- chrony.conf: enable 'log tracking' (idempotent) so chronyd appends
source/stratum/offset to /var/log/chrony/tracking.log. Write volume is a ~130B
line per clock update (backing off to ~maxpoll when stable) and capped by the
chrony RPM's logrotate — negligible on the RAM overlay. cmdport 0 stays, so no
STIG deviation.
- agent: chronyTracking() now reads the last data line of tracking.log via
parseTrackingLog() (source f[2], stratum f[3], offset f[6], leap/sync f[7]);
replaces the chronyc exec + parseChrony. Unit test swapped accordingly.
- revert the two abandoned approaches: drop the bindcmdaddress line (394ad10)
and the fleet_agent_chronyc SELinux nnp_transition module + provisioner block
(e6fd4a2, .te deleted) — no chronyc exec means no transition to allow. Removed
stig-deviations #16 and #17 (both waivers no longer needed).
Needs a workstation image rebuild + reboot. BENCH-VERIFY: tracking.log is
world-readable so the DynamicUser agent can read it; under enforcing
unconfined_service_t can read chronyd_var_log_t (add a minimal file-read allow
if denied); and the offset sign matches chronyc on a synced host.
Audiobuzz
4ca0b6dd06