Be stricter about JSON that is accepted by Synapse (#8106)

1 files changed, 2 insertions, 3 deletions

diff --git a/synapse/federation/sender/transaction_manager.py b/synapse/federation/sender/transaction_manager.py

index c7f6cb3d73..9bd534a313 100644
--- a/synapse/federation/sender/transaction_manager.py
+++ b/synapse/federation/sender/transaction_manager.py
@@ -15,8 +15,6 @@
 import logging
 from typing import TYPE_CHECKING, List, Tuple
 
-from canonicaljson import json
-
 from synapse.api.errors import HttpResponseException
 from synapse.events import EventBase
 from synapse.federation.persistence import TransactionActions
@@ -28,6 +26,7 @@ from synapse.logging.opentracing import (
     tags,
     whitelisted_homeserver,
 )
+from synapse.util import json_decoder
 from synapse.util.metrics import measure_func
 
 if TYPE_CHECKING:
@@ -71,7 +70,7 @@ class TransactionManager(object):
         for edu in pending_edus:
             context = edu.get_context()
             if context:
-                span_contexts.append(extract_text_map(json.loads(context)))
+                span_contexts.append(extract_text_map(json_decoder.decode(context)))
             if keep_destination:
                 edu.strip_context()