Make `check_event_allowed` module API callback not fail open (accept events) when an exception is raised (#11033)

1 files changed, 5 insertions, 4 deletions

diff --git a/synapse/events/third_party_rules.py b/synapse/events/third_party_rules.py
index 8816ef4b76..1bb8ca7145 100644
--- a/synapse/events/third_party_rules.py
+++ b/synapse/events/third_party_rules.py
@@ -14,7 +14,7 @@
 import logging
 from typing import TYPE_CHECKING, Any, Awaitable, Callable, List, Optional, Tuple
 
-from synapse.api.errors import SynapseError
+from synapse.api.errors import ModuleFailedException, SynapseError
 from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.types import Requester, StateMap
@@ -233,9 +233,10 @@ class ThirdPartyEventRules:
                 # This module callback needs a rework so that hacks such as
                 # this one are not necessary.
                 raise e
-            except Exception as e:
-                logger.warning("Failed to run module API callback %s: %s", callback, e)
-                continue
+            except Exception:
+                raise ModuleFailedException(
+                    "Failed to run `check_event_allowed` module API callback"
+                )
 
             # Return if the event shouldn't be allowed or if the module came up with a
             # replacement dict for the event.