fix: issue 1641 database session service leaks events

src/google/adk/sessions/database_session_service.py

@@ -460,6 +460,7 @@ async def get_session(
       storage_events = (
           session_factory.query(StorageEvent)
           .filter(StorageEvent.session_id == storage_session.id)
+          .filter(StorageEvent.user_id == user_id)
           .filter(timestamp_filter)
           .order_by(StorageEvent.timestamp.desc())
           .limit(

tests/unittests/sessions/test_session_service.py

@@ -126,6 +126,7 @@ async def test_session_state(service_type):
   app_name = 'my_app'
   user_id_1 = 'user1'
   user_id_2 = 'user2'
+  user_id_malicious = 'malicious'
   session_id_11 = 'session11'
   session_id_12 = 'session12'
   session_id_2 = 'session2'
@@ -148,6 +149,10 @@ async def test_session_state(service_type):
       app_name=app_name, user_id=user_id_2, session_id=session_id_2
   )
 
+  await session_service.create_session(
+      app_name=app_name, user_id=user_id_malicious, session_id=session_id_11
+  )
+
   assert session_11.state.get('key11') == 'value11'
 
   event = Event(
@@ -196,6 +201,13 @@ async def test_session_state(service_type):
   assert session_11.state.get('user:key1') == 'value1'
   assert not session_11.state.get('temp:key')
 
+  # Make sure a malicious user can obtain a session and events not belonging to them
+  session_mismatch = await session_service.get_session(
+      app_name=app_name, user_id=user_id_malicious, session_id=session_id_11
+  )
+
+  assert len(session_mismatch.events) == 0
+
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize(