Problem:
When UnifiedLock.__aexit__ encountered an exception during async_lock.release(),
the error recovery logic would incorrectly attempt to release async_lock again
because it only checked main_lock_released flag. This could cause:
- Double-release attempts on already-failed locks
- Masking of original exceptions
- Undefined behavior in lock state
Root Cause:
The recovery logic used only main_lock_released to determine whether to attempt
async_lock release, without tracking whether async_lock.release() had already
been attempted and failed.
Fix:
- Added async_lock_released flag to track async_lock release attempts
- Updated recovery logic condition to check both main_lock_released AND
async_lock_released before attempting async_lock release
- This ensures async_lock.release() is only called once, even if it fails
Testing:
- Added test_aexit_no_double_release_on_async_lock_failure:
Verifies async_lock.release() is called only once when it fails
- Added test_aexit_recovery_on_main_lock_failure:
Verifies recovery logic still works when main lock fails
- All 5 UnifiedLock safety tests pass
Impact:
- Eliminates double-release bugs in multiprocess lock scenarios
- Preserves correct error propagation
- Maintains recovery logic for legitimate failure cases
Files Modified:
- lightrag/kg/shared_storage.py: Added async_lock_released tracking
- tests/test_unified_lock_safety.py: Added 2 new tests (5 total now pass)
Why this change is needed:
Two critical P0 security vulnerabilities were identified in CursorReview:
1. UnifiedLock silently allows unprotected execution when lock is None, creating
false security and potential race conditions in multi-process scenarios
2. PostgreSQL migration copies ALL workspace data during legacy table migration,
violating multi-tenant isolation and causing data leakage
How it solves it:
- UnifiedLock now raises RuntimeError when lock is None instead of WARNING
- Added workspace parameter to setup_table() for proper data isolation
- Migration queries now filter by workspace in both COUNT and SELECT operations
- Added clear error messages to help developers diagnose initialization issues
Impact:
- lightrag/kg/shared_storage.py: UnifiedLock raises exception on None lock
- lightrag/kg/postgres_impl.py: Added workspace filtering to migration logic
- tests/test_unified_lock_safety.py: 3 tests for lock safety
- tests/test_workspace_migration_isolation.py: 3 tests for workspace isolation
- tests/test_dimension_mismatch.py: Updated table names and mocks
- tests/test_postgres_migration.py: Updated mocks for workspace filtering
Testing:
- All 31 tests pass (16 migration + 4 safety + 3 lock + 3 workspace + 5 dimension)
- Backward compatible: existing code continues working unchanged
- Code style verified with ruff and pre-commit hooks
