diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index 6d8e48ed39..50cea3f378 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -26,6 +26,7 @@ from synapse.api.errors import (
FederationDeniedError,
HttpResponseException,
RequestSendFailed,
+ SynapseError,
)
from synapse.logging.opentracing import log_kv, set_tag, trace
from synapse.types import RoomStreamToken, get_domain_from_id
@@ -39,6 +40,8 @@ from ._base import BaseHandler
logger = logging.getLogger(__name__)
+MAX_DEVICE_DISPLAY_NAME_LEN = 100
+
class DeviceWorkerHandler(BaseHandler):
def __init__(self, hs):
@@ -404,9 +407,18 @@ class DeviceHandler(DeviceWorkerHandler):
defer.Deferred:
"""
+ # Reject a new displayname which is too long.
+ new_display_name = content.get("display_name")
+ if new_display_name and len(new_display_name) > MAX_DEVICE_DISPLAY_NAME_LEN:
+ raise SynapseError(
+ 400,
+ "Device display name is too long (max %i)"
+ % (MAX_DEVICE_DISPLAY_NAME_LEN,),
+ )
+
try:
yield self.store.update_device(
- user_id, device_id, new_display_name=content.get("display_name")
+ user_id, device_id, new_display_name=new_display_name
)
yield self.notify_device_update(user_id, [device_id])
except errors.StoreError as e:
|
