From 6920d88892e77aec787b6afc0e01e6e09dc36216 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Mon, 16 Dec 2019 13:14:37 +0000 Subject: [PATCH] Exclude rejected state events when calculating state at backwards extrems (#6527) This fixes a weird bug where, if you were determined enough, you could end up with a rejected event forming part of the state at a backwards-extremity. Authing that backwards extrem would then lead to us trying to pull the rejected event from the db (with allow_rejected=False), which would fail with a 404. --- changelog.d/6527.bugfix | 1 + synapse/handlers/federation.py | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) create mode 100644 changelog.d/6527.bugfix diff --git a/changelog.d/6527.bugfix b/changelog.d/6527.bugfix new file mode 100644 index 000000000..53214b074 --- /dev/null +++ b/changelog.d/6527.bugfix @@ -0,0 +1 @@ +Fix a bug which could cause the federation server to incorrectly return errors when handling certain obscure event graphs. \ No newline at end of file diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 3f480f205..3fccccfec 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -605,7 +605,7 @@ class FederationHandler(BaseHandler): remote_event = event_map.get(event_id) if not remote_event: raise Exception("Unable to get missing prev_event %s" % (event_id,)) - if remote_event.is_state(): + if remote_event.is_state() and remote_event.rejected_reason is None: remote_state.append(remote_event) auth_chain = [event_map[e_id] for e_id in auth_event_ids if e_id in event_map]