Redact the MAC in the reservations unsubscribe warning

[eman]

Problem

fetch_reservations logged device_info.mac_address in the clear when its cleanup unsubscribe raised:

except Exception:
    _logger.warning(
        "Failed to unsubscribe reservations response handler for device %s",
        device.device_info.mac_address,   # unredacted
        exc_info=True,
    )

The identical warning in update_reservations_confirmed, seventy lines below in the same file, already passes the value through redact_mac. This call site was simply missed.

CodeQL has flagged it as py/clear-text-logging-sensitive-data (high severity) since 2026-07-23, and it shipped in 9.3.1.

Fix

Both call sites now redact. The function-local from .mqtt.utils import redact_mac matches the sibling and the three other call sites in the package (tou_schedule.py, device_info_cache.py, mqtt/client.py), all of which import it inside the function rather than at module scope.

I grepped for other unredacted mac_address/device_mac values reaching a logger — this was the only one.

Tests

test_fetch_reservations_redacts_mac_when_unsubscribe_fails drives the cleanup path with a failing unsubscribe and asserts the MAC does not appear in the emitted warning. Verified it fails against the unredacted version and passes with the fix. Full suite: 736 passed.

https://claude.ai/code/session_01XVj9BYvuLj7Th3iFUVoeCn

[Copilot]

🟢 Approval recommended

The change is narrowly scoped, consistent with existing redaction patterns in the codebase, and includes a targeted regression test.

Pull request overview

This PR addresses a security logging issue in the reservations helpers by ensuring device MAC addresses are redacted in a warning emitted when an unsubscribe cleanup step fails. It aligns fetch_reservations with the already-redacting behavior in update_reservations_confirmed and adds a regression test to prevent reintroducing clear-text MAC logging.

Changes:

• Redact device.device_info.mac_address in the fetch_reservations unsubscribe-failure warning (matching the existing redaction in update_reservations_confirmed).
• Add a unit test that forces the unsubscribe failure path and asserts the clear-text MAC does not appear in the warning output.
• Document the security fix in the Unreleased changelog.

File summaries

File	Description
src/nwp500/reservations.py	Redacts MAC address in the unsubscribe failure warning in fetch_reservations.
tests/test_reservations.py	Adds regression coverage ensuring clear-text MAC is not logged when unsubscribe fails.
CHANGELOG.rst	Notes the security-related logging redaction fix under Unreleased.

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 0
• Review effort level: Lite

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