1.7.3

When we have an event which refers to non-existent auth_events, ignore said events rather than exploding in a ball of fire.

Fixes #6605.

CHANGES.md

@@ -1,3 +1,14 @@
+Synapse 1.7.3 (2019-12-31)
+==========================
+
+This release fixes a long-standing bug in the state resolution algorithm.
+
+Bugfixes
+--------
+
+- Fix exceptions caused by state resolution choking on malformed events. ([\#6608](https://github.com/matrix-org/synapse/issues/6608))
+
+
 Synapse 1.7.2 (2019-12-20)
 ==========================
 

README.rst

@@ -393,4 +393,4 @@ something like the following in their logs::
     2019-09-11 19:32:04,271 - synapse.federation.transport.server - 288 - WARNING - GET-11752 - authenticate_request failed: 401: Invalid signature for server <server> with key ed25519:a_EqML: Unable to verify signature for <server>
 
 This is normally caused by a misconfiguration in your reverse-proxy. See
-`<docs/reverse_proxy.rst>`_ and double-check that your settings are correct.
+`<docs/reverse_proxy.md>`_ and double-check that your settings are correct.

debian/changelog

@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.7.3) stable; urgency=medium
+
+  * New synapse release 1.7.3.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 31 Dec 2019 10:45:04 +0000
+
 matrix-synapse-py3 (1.7.2) stable; urgency=medium
 
   * New synapse release 1.7.2.

docs/sample_log_config.yaml

@@ -0,0 +1,43 @@
+# Example log config file for synapse.
+#
+# This is a YAML file containing a standard Python logging configuration
+# dictionary. See [1] for details on the valid settings.
+#
+# [1]: https://docs.python.org/3.7/library/logging.config.html#configuration-dictionary-schema
+
+version: 1
+
+formatters:
+    precise:
+        format: '%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(request)s - %(message)s'
+
+filters:
+    context:
+        (): synapse.logging.context.LoggingContextFilter
+        request: ""
+
+handlers:
+    file:
+        class: logging.handlers.RotatingFileHandler
+        formatter: precise
+        filename: /home/rav/work/synapse/homeserver.log
+        maxBytes: 104857600
+        backupCount: 10
+        filters: [context]
+        encoding: utf8
+    console:
+        class: logging.StreamHandler
+        formatter: precise
+        filters: [context]
+
+loggers:
+    synapse.storage.SQL:
+        # beware: increasing this to DEBUG will make synapse log sensitive
+        # information such as access tokens.
+        level: INFO
+
+root:
+    level: INFO
+    handlers: [file, console]
+
+disable_existing_loggers: false

docs/workers.md

@@ -196,7 +196,7 @@ Handles the media repository. It can handle all endpoints starting with:
 
     /_matrix/media/
 
-And the following regular expressions matching media-specific administration APIs:
+... and the following regular expressions matching media-specific administration APIs:
 
     ^/_synapse/admin/v1/purge_media_cache$
     ^/_synapse/admin/v1/room/.*/media$
@@ -206,6 +206,18 @@ You should also set `enable_media_repo: False` in the shared configuration
 file to stop the main synapse running background jobs related to managing the
 media repository.
 
+In the `media_repository` worker configuration file, configure the http listener to
+expose the `media` resource. For example:
+
+```yaml
+    worker_listeners:
+     - type: http
+       port: 8085
+       resources:
+         - names:
+           - media
+```
+
 Note this worker cannot be load-balanced: only one instance should be active.
 
 ### `synapse.app.client_reader`

synapse/__init__.py

@@ -36,7 +36,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.7.2"
+__version__ = "1.7.3"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when

synapse/state/v2.py

@@ -183,16 +183,20 @@ def _get_power_level_for_sender(room_id, event_id, event_map, state_res_store):
 
     pl = None
     for aid in event.auth_event_ids():
-        aev = yield _get_event(room_id, aid, event_map, state_res_store)
-        if (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
+        aev = yield _get_event(
+            room_id, aid, event_map, state_res_store, allow_none=True
+        )
+        if aev and (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
             pl = aev
             break
 
     if pl is None:
         # Couldn't find power level. Check if they're the creator of the room
         for aid in event.auth_event_ids():
-            aev = yield _get_event(room_id, aid, event_map, state_res_store)
-            if (aev.type, aev.state_key) == (EventTypes.Create, ""):
+            aev = yield _get_event(
+                room_id, aid, event_map, state_res_store, allow_none=True
+            )
+            if aev and (aev.type, aev.state_key) == (EventTypes.Create, ""):
                 if aev.content.get("creator") == event.sender:
                     return 100
                 break
@@ -403,10 +407,17 @@ def _iterative_auth_checks(
 
         auth_events = {}
         for aid in event.auth_event_ids():
-            ev = yield _get_event(room_id, aid, event_map, state_res_store)
+            ev = yield _get_event(
+                room_id, aid, event_map, state_res_store, allow_none=True
+            )
 
-            if ev.rejected_reason is None:
-                auth_events[(ev.type, ev.state_key)] = ev
+            if not ev:
+                logger.warning(
+                    "auth_event id %s for event %s is missing", aid, event_id
+                )
+            else:
+                if ev.rejected_reason is None:
+                    auth_events[(ev.type, ev.state_key)] = ev
 
         for key in event_auth.auth_types_for_event(event):
             if key in resolved_state:
@@ -457,8 +468,10 @@ def _mainline_sort(
         auth_events = pl_ev.auth_event_ids()
         pl = None
         for aid in auth_events:
-            ev = yield _get_event(room_id, aid, event_map, state_res_store)
-            if (ev.type, ev.state_key) == (EventTypes.PowerLevels, ""):
+            ev = yield _get_event(
+                room_id, aid, event_map, state_res_store, allow_none=True
+            )
+            if ev and (ev.type, ev.state_key) == (EventTypes.PowerLevels, ""):
                 pl = aid
                 break
 
@@ -506,8 +519,10 @@ def _get_mainline_depth_for_event(event, mainline_map, event_map, state_res_stor
         event = None
 
         for aid in auth_events:
-            aev = yield _get_event(room_id, aid, event_map, state_res_store)
-            if (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
+            aev = yield _get_event(
+                room_id, aid, event_map, state_res_store, allow_none=True
+            )
+            if aev and (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
                 event = aev
                 break
 
@@ -516,7 +531,7 @@ def _get_mainline_depth_for_event(event, mainline_map, event_map, state_res_stor
 
 
 @defer.inlineCallbacks
-def _get_event(room_id, event_id, event_map, state_res_store):
+def _get_event(room_id, event_id, event_map, state_res_store, allow_none=False):
     """Helper function to look up event in event_map, falling back to looking
     it up in the store
 
@@ -525,15 +540,22 @@ def _get_event(room_id, event_id, event_map, state_res_store):
         event_id (str)
         event_map (dict[str,FrozenEvent])
         state_res_store (StateResolutionStore)
+        allow_none (bool): if the event is not found, return None rather than raising
+            an exception
 
     Returns:
-        Deferred[FrozenEvent]
+        Deferred[Optional[FrozenEvent]]
     """
     if event_id not in event_map:
         events = yield state_res_store.get_events([event_id], allow_rejected=True)
         event_map.update(events)
-    event = event_map[event_id]
-    assert event is not None
+    event = event_map.get(event_id)
+
+    if event is None:
+        if allow_none:
+            return None
+        raise Exception("Unknown event %s" % (event_id,))
+
     if event.room_id != room_id:
         raise Exception(
             "In state res for room %s, event %s is in %s"