StateFilter.must_await_full_state falls over if called on a StateFilters for membership events with a bogus state key #13040
Description
IndexError: list index out of range
File "synapse/http/server.py", line 366, in _async_render_wrapper
callback_return = await self._async_render(request)
File "synapse/http/server.py", line 572, in _async_render
callback_return = await raw_callback_return
File "synapse/rest/client/room.py", line 167, in on_GET
data = await msg_handler.get_room_data(
File "synapse/handlers/message.py", line 128, in get_room_data
data = await self._storage_controllers.state.get_current_state_event(
File "synapse/storage/controllers/state.py", line 482, in get_current_state_event
state_map = await self.get_current_state(
File "synapse/storage/controllers/state.py", line 464, in get_current_state
state_map_ids = await self.get_current_state_ids(room_id, state_filter)
File "synapse/storage/controllers/state.py", line 392, in get_current_state_ids
if not state_filter or state_filter.must_await_full_state(self._is_mine_id):
File "synapse/storage/state.py", line 563, in must_await_full_state
if not is_mine_id(state_key):
File "synapse/server.py", line 341, in is_mine_id
return string.split(":", 1)[1] == self.hostname
Matrix.org received a request of the form GET /_matrix/client/r0/rooms/ROOM_IDstate/m.room.member/foo@example.com. After checking the requester is in the room, we lookup the given state key in our server's view of the room.:
synapse/synapse/handlers/message.py
Lines 127 to 130 in a164a46
This constructs a StateFilter looking for events matching that (type, state_key) pair.
synapse/synapse/storage/controllers/state.py
Lines 479 to 488 in 7c6b220
We eventually fall into must_await_full_state. Because the event is a membership event, we check to see if the sender is local.
synapse/synapse/storage/state.py
Lines 561 to 566 in 7c6b220
But is_mind_id throws because the given state_key doesn't contain a colon.
Lines 339 to 341 in 1e45305
Options that spring to mind:
- Add a try/except wrapper around
is_mine_id. Any failure means the fancy faster join stuff is not available. - At the rest level, validate that the state_key is a matrix ID when the type is m.room.membership. The spec would allow us to return 404 Not Found in this case.
Related: #12489. I don't think this is directly related to faster joins; rather it's collateral damage? Might be of interest to @richvdh anyway.