wifi-densepose/v2/crates/homecore/src
rUv bf1dfe79fd
fix(homecore core): TOCTOU race dropped/reordered state_changed events under concurrent writers (~93k→0) + 2 fail-closed hardenings (#1087)
* fix(homecore): atomic state set — close TOCTOU lost/reordered state_changed events

StateMachine::set did get() (release shard lock) → compute next + no-op
decision → insert() (re-acquire lock) → send(). The read-modify-write was
not atomic w.r.t. a concurrent writer on the same entity: a writer that
read a stale `old` could mis-classify a real transition as a no-op and drop
its state_changed event (a missed automation trigger) or fire an event whose
new_state duplicated the previously delivered one (a spurious trigger for any
automation keyed on old_state != new_state). ADR-127 §2.1 promises "writer
atomically replaces the map entry"; the implementation did not.

Fix: hold the DashMap shard write-lock across the whole read→decide→insert→
fire sequence via entry()/insert_entry(). tx.send is non-blocking, non-async,
and never re-enters the map, so firing under the shard lock cannot deadlock
and keeps global event order in lock-step with global commit order.

Pinned by concurrent_set_fires_no_duplicate_adjacent_events: 4 writers
toggling one entity A/B; asserts no two consecutive fired events carry the
same new_state (impossible under correct serialisation). Fails reliably on
the old code (~365-476 duplicate-adjacent events on the first trial), passes
on the fix across repeated runs.

Co-Authored-By: claude-flow <ruv@ruv.net>

* harden(homecore): bound entity_id length — close memory-DoS at the REST boundary

homecore-api/src/rest.rs parses untrusted path segments straight through
EntityId::parse (get/delete/set_state). With no length cap, an otherwise-valid
id like "a." + many MB of [a-z0-9_] was accepted; a POST /api/states/<giant>
would persist it into the DashMap state store, permanently growing memory
(amplification across distinct ids).

Fix: reject ids longer than MAX_ENTITY_ID_LEN (255, HA-compatible) up front in
parse(), before any per-char scan, with a new EntityIdError::TooLong. Fails
closed at the boundary type so every caller (REST, registry deserialize,
automation) is protected.

Pinned by entity_id_length_boundary: exactly-MAX accepted, MAX+1 rejected,
4 MiB id rejected as TooLong. Fails on old code (oversized parses Ok).

Co-Authored-By: claude-flow <ruv@ruv.net>

* harden(homecore): isolate panicking service handlers (catch_unwind)

ServiceRegistry::call already ran handlers outside the registry lock (the
Arc<dyn ServiceHandler> is cloned out of the read guard first), so a panic
could never poison the RwLock or block other callers — good. But a panicking
handler unwound through call() into the caller's task; the task driving the
engine (e.g. an axum request handler invoking a service) could be aborted by
one buggy integration.

Fix: wrap the handler future in AssertUnwindSafe + FutureExt::catch_unwind and
convert a panic into ServiceError::HandlerPanicked. Mirrors HA isolating
service-handler exceptions. The registry stays fully usable afterwards.

Pinned by panicking_handler_is_isolated_and_registry_survives: the panicking
call returns HandlerPanicked (not an unwind), a sibling healthy service still
returns its value, and the bad service remains registered. Fails on old code
(the await point panics instead of returning Err).

Co-Authored-By: claude-flow <ruv@ruv.net>

* test(homecore): pin event-bus lag safety (bounded broadcast, no DoS)

Documents-with-evidence that the core EventBus does NOT have the homecore-api
WS broadcast-lag failure: with EVENT_CHANNEL_CAPACITY=4096, firing 3x capacity
while a subscriber never drains keeps fire_* non-blocking (publisher never
waits on slow receivers), gives the slow receiver a recoverable Lagged(n)
(drop-oldest + re-sync) rather than a closed channel, and leaves the bus live
for a fresh fast subscriber. No code change — pins the clean dimension.

Co-Authored-By: claude-flow <ruv@ruv.net>

* docs(homecore): record ADR-127 §9 security+concurrency review + CHANGELOG

Documents the three pinned fixes (HC-RACE-01 state-set TOCTOU, HC-EID-LEN-01
entity_id memory-DoS, HC-SVC-PANIC-01 service-handler isolation) and the
clean dimensions (bounded event-bus lag handling, lock discipline / no
lock-across-await, no panic-on-input) with their evidence.

Co-Authored-By: claude-flow <ruv@ruv.net>
2026-06-14 22:28:05 -04:00
..
bus.rs fix(homecore core): TOCTOU race dropped/reordered state_changed events under concurrent writers (~93k→0) + 2 fail-closed hardenings (#1087) 2026-06-14 22:28:05 -04:00
entity.rs fix(homecore core): TOCTOU race dropped/reordered state_changed events under concurrent writers (~93k→0) + 2 fail-closed hardenings (#1087) 2026-06-14 22:28:05 -04:00
event.rs HOMECORE: native Rust/WASM/TS port of Home Assistant — ADRs 125-134 implementation (#800) 2026-05-25 22:47:48 -04:00
homecore.rs HOMECORE: native Rust/WASM/TS port of Home Assistant — ADRs 125-134 implementation (#800) 2026-05-25 22:47:48 -04:00
lib.rs HOMECORE: native Rust/WASM/TS port of Home Assistant — ADRs 125-134 implementation (#800) 2026-05-25 22:47:48 -04:00
registry.rs HOMECORE: native Rust/WASM/TS port of Home Assistant — ADRs 125-134 implementation (#800) 2026-05-25 22:47:48 -04:00
service.rs fix(homecore core): TOCTOU race dropped/reordered state_changed events under concurrent writers (~93k→0) + 2 fail-closed hardenings (#1087) 2026-06-14 22:28:05 -04:00
state.rs fix(homecore core): TOCTOU race dropped/reordered state_changed events under concurrent writers (~93k→0) + 2 fail-closed hardenings (#1087) 2026-06-14 22:28:05 -04:00