diff options
| -rw-r--r-- | changelog.d/4535.bugfix | 1 | ||||
| -rw-r--r-- | synapse/storage/events_worker.py | 37 |
2 files changed, 33 insertions, 5 deletions
diff --git a/changelog.d/4535.bugfix b/changelog.d/4535.bugfix new file mode 100644 index 0000000000..facd344cdd --- /dev/null +++ b/changelog.d/4535.bugfix @@ -0,0 +1 @@ +Fix infinite loop when an event is redacted in a v3 room diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py index 57dae324c7..1716be529a 100644 --- a/synapse/storage/events_worker.py +++ b/synapse/storage/events_worker.py @@ -161,6 +161,12 @@ class EventsWorkerStore(SQLBaseStore): log_ctx = LoggingContext.current_context() log_ctx.record_event_fetch(len(missing_events_ids)) + # Note that _enqueue_events is also responsible for turning db rows + # into FrozenEvents (via _get_event_from_row), which involves seeing if + # the events have been redacted, and if so pulling the redaction event out + # of the database to check it. + # + # _enqueue_events is a bit of a rubbish name but naming is hard. missing_events = yield self._enqueue_events( missing_events_ids, allow_rejected=allow_rejected, @@ -179,14 +185,35 @@ class EventsWorkerStore(SQLBaseStore): # instead. if not allow_rejected and entry.event.type == EventTypes.Redaction: if entry.event.internal_metadata.need_to_check_redaction(): - orig = yield self.get_event( - entry.event.redacts, + # XXX: we need to avoid calling get_event here. + # + # The problem is that we end up at this point when an event + # which has been redacted is pulled out of the database by + # _enqueue_events, because _enqueue_events needs to check the + # redaction before it can cache the redacted event. So obviously, + # calling get_event to get the redacted event out of the database + # gives us an infinite loop. + # + # For now (quick hack to fix during 0.99 release cycle), we just + # go and fetch the relevant row from the db, but it would be nice + # to think about how we can cache this rather than hit the db + # every time we access a redaction event. + # + # One thought on how to do this: + # 1. split _get_events up so that it is divided into (a) get the + # rawish event from the db/cache, (b) do the redaction/rejection + # filtering + # 2. have _get_event_from_row just call the first half of that + + orig_sender = yield self._simple_select_one_onecol( + table="events", + keyvalues={"event_id": entry.event.redacts}, + retcol="sender", allow_none=True, - allow_rejected=True, - get_prev_content=False, ) + expected_domain = get_domain_from_id(entry.event.sender) - if orig and get_domain_from_id(orig.sender) == expected_domain: + if orig_sender and get_domain_from_id(orig_sender) == expected_domain: # This redaction event is allowed. Mark as not needing a # recheck. entry.event.internal_metadata.recheck_redaction = False |