PR #16858's session-scoped interactive sudo password cache falls back to
a thread-identity scope when no HERMES_SESSION_KEY is bound. ACP never
set that contextvar, so two ACP sessions landing on the same reused
ThreadPoolExecutor thread still shared the cache — the exact scenario
the PR headlined.
acp_adapter/server.py now:
- binds HERMES_SESSION_KEY=<session_id> via gateway.session_context
inside _run_agent() (and clears on exit)
- wraps the loop.run_in_executor(_executor, _run_agent) call in a fresh
contextvars.copy_context() so concurrent ACP sessions don't stomp on
each other's ContextVar writes (executor pool threads would otherwise
share a context).
Adds tests/acp/test_approval_isolation.py::
test_sudo_password_cache_isolated_across_acp_sessions_on_same_pool_thread
which drives two back-to-back sessions through a 1-worker ThreadPoolExecutor
and asserts B does not observe A's cached password.
Two related ACP approval issues:
GHSA-96vc-wcxf-jjff — ACP's _run_agent never set HERMES_INTERACTIVE
(or any other flag recognized by tools.approval), so check_all_command_guards
took the non-interactive auto-approve path and never consulted the
ACP-supplied approval callback (conn.request_permission). Dangerous
commands executed in ACP sessions without operator approval despite
the callback being installed. Fix: set HERMES_INTERACTIVE=1 around
the agent run so check_all_command_guards routes through
prompt_dangerous_approval(approval_callback=...) — the correct shape
for ACP's per-session request_permission call. HERMES_EXEC_ASK would
have routed through the gateway-queue path instead, which requires a
notify_cb registered in _gateway_notify_cbs (not applicable to ACP).
GHSA-qg5c-hvr5-hjgr — _approval_callback and _sudo_password_callback
were module-level globals in terminal_tool. Concurrent ACP sessions
running in ThreadPoolExecutor threads each installed their own callback
into the same slot, racing. Fix: store both callbacks in threading.local()
so each thread has its own slot. CLI mode (single thread) is unaffected;
gateway mode uses a separate queue-based approval path and was never
touched.
set_approval_callback is now called INSIDE _run_agent (the executor
thread) rather than before dispatching — so the TLS write lands on the
correct thread.
Tests: 5 new in tests/acp/test_approval_isolation.py covering
thread-local isolation of both callbacks and the HERMES_INTERACTIVE
callback routing. Existing tests/acp/ (159 tests) and tests/tools/
approval-related tests continue to pass.
Fixes GHSA-96vc-wcxf-jjff
Fixes GHSA-qg5c-hvr5-hjgr
