diff options
| -rw-r--r-- | changelog.d/7859.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/federation.py | 15 |
2 files changed, 14 insertions, 2 deletions
diff --git a/changelog.d/7859.bugfix b/changelog.d/7859.bugfix new file mode 100644 index 0000000000..19cff4b061 --- /dev/null +++ b/changelog.d/7859.bugfix @@ -0,0 +1 @@ +Fix a bug which allowed empty rooms to be rejoined over federation. diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index e43bccd721..df885e45e8 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -44,6 +44,7 @@ from synapse.api.errors import ( FederationDeniedError, FederationError, HttpResponseException, + NotFoundError, RequestSendFailed, SynapseError, ) @@ -1439,10 +1440,20 @@ class FederationHandler(BaseHandler): ) raise SynapseError(403, "User not from origin", Codes.FORBIDDEN) - event_content = {"membership": Membership.JOIN} - + # checking the room version will check that we've actually heard of the room + # (and return a 404 otherwise) room_version = await self.store.get_room_version_id(room_id) + # now check that we are *still* in the room + is_in_room = await self.auth.check_host_in_room(room_id, self.server_name) + if not is_in_room: + logger.info( + "Got /make_join request for room %s we are no longer in", room_id, + ) + raise NotFoundError("Not an active room on this server") + + event_content = {"membership": Membership.JOIN} + builder = self.event_builder_factory.new( room_version, { |