Three robustness/hardening fixes surfaced by /sh-security-review on the
agent-team listener/coordinator surface. None alter AUTHZ-01 allowlist
behavior or the first-answer-wins compare-and-set semantics.
1. Respawn close() leak (CWE-772). The watchdog _supervise_slack_listener
respawned the inbound Slack listener without tearing down the dead one,
leaking a Socket Mode WebSocket / SDK thread set per flap. Now the dead
listener is closed before respawn (new _close_dead_listener, idempotent),
AND _run_listener has a finally that always closes the listener so a
crashed serve() releases its socket. SlackListener.close() is idempotent,
so the belt-and-braces close stays a safe no-op.
2. Broadened exception guard in handle_event (CWE-248). The submit block
only caught ValueError; the accept path (submit_answer ->
_question_turn/_question_thread) can raise KeyError on a concurrently
mutated row, and the CAS can raise sqlite3.Error. An uncaught exception
would escape into the Bolt dispatch. Added a separate `except Exception`
that logs at WARNING (not silent, not debug) and returns None. The
existing ValueError-as-debug behavior is unchanged; authorization still
runs first, so the trust boundary is not widened.
3. channel_ref partial-unique index (defense-in-depth). Added
uq_pending_questions_open_channel_ref — a PARTIAL UNIQUE index on
(channel_ref) WHERE channel_ref IS NOT NULL AND status='open' — so two
OPEN rows can never share a non-null channel_ref (a thread_ts can never
map to two open questions). Installed in init_db AND unconditionally in
migrate (idempotent IF NOT EXISTS) so existing v1 DBs gain it. NULLs and
closed rows are excluded; mirrored verbatim into schema.sql.
Tests: +8 (was 960, now 968). New: schema partial-unique reject/null/closed/
migrate cases; handle_event KeyError + sqlite3.Error swallow cases;
coordinator close-before-respawn + run_listener-closes-on-crash. Fixed the
operator-cli test fixture to use a per-question channel_ref (it previously
inserted multiple open rows sharing one ref, which the new index correctly
rejects).
Addresses the confirmed findings from /sh-security-review + the GPT-4.1
cross-review of the Plane-2 scaffold. Full suite: 589 passed; ruff clean.
FIXED (proven-exploitable):
- CI-guard denylist bypass (HIGH): Python fnmatch '**/' is non-recursive, so
root-level template.yaml/*.tf/cdk.json/*.pem/*.key/*-stack.* evaded the
trust-control surface. Replaced fnmatch with a recursive, case-insensitive
glob->regex matcher. (verified: fnmatch('template.yaml','**/template.yaml')==False)
- CI-guard scope bypass (HIGH): a '**' declared_scope made every path in-scope.
Scope is now concrete-prefix confinement (reduces a glob to its leading
metacharacter-free segments; '**' -> empty -> dropped -> unscoped reject).
- Box-side vs CI denylist divergence (MED): builders.py _DENY_PATTERNS now covers
Terraform, *.pem/*.key, CDK stack files, .github/actions, *iam*, bare policy*.json
(case-insensitive), matching the CI surface.
- force-resume was backwards (MED): it superseded the answered row recovery
resumes from, making a stuck task permanently un-resumable while printing
success. Now re-opens an EXPIRED (parked) question via a new reopen_question
CAS helper; never supersedes an answered row; honest exit codes.
- operator attribution (MED): run-team.py --operator defaulted to "" -> now the
OS login, so destructive actions are always attributable.
- audit-log append race (MED): replaced read-modify-rewrite (lost records under
concurrent operators) with an O_APPEND single-line write, mode 600 enforced.
- lstrip("ab/") path-mangling in the symlink error path -> regex prefix strip.
Regression tests added across test_ci_gate_workflow / test_builders / test_run_team
/ test_schema. Design-level findings (resume-worker durability, egress breadth,
answered_at ordering, DB-swap TOCTOU, diff-hash threat-model) are pre-deployment
/ P1-build-proper and recorded with written justification in
agent-team/.security-review/suppressions.json; CI README diff-hash wording made
honest.
Resolves three execution-proven verifier findings from the scaffold review.
Full suite: 548 passed, 1 skipped (stable across repeated runs); ruff clean.
builders denylist (§3.3.2 #2): scan was +++-only and missed header-only
sections. Now section-driven off `diff --git a/<src> b/<dest>`, catching the 4
proven bypasses — delete of a denied path, mode-change-only, `copy to` a denied
path, out-of-scope delete (regression tests for each).
§3.3.1 compare-and-set concurrency: BEGIN IMMEDIATE moved inside guarded retry;
each CAS now runs on its own connection (shared sqlite3.Connection cannot hold
two transactions, and is unsafe for concurrent use even for reads). connect()
stashes the db path on a Connection subclass so the path is derived by a
thread-safe attribute read, not a PRAGMA on the shared conn; busy_timeout set
before the WAL pragma. Added shared-connection concurrent regression tests
(distinct + same question) — previously raised "transaction within a
transaction".
operator CLI (run-team.py): added the design-named re-deliver and force-resume
verbs (were missing); audit now records the attempt BEFORE the mutation and the
outcome after, so a ledger mutation can never land without a trail; main()
catches OSError instead of leaving an uncaught traceback on audit-write failure.
