From 02d99f044efbed3c347c19a430d56cfbb41c87a7 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Mon, 24 Jan 2022 09:38:37 -0500 Subject: [PATCH] Apply a timeout to reading the body when fetching a file. (#11784) This prevents the URL preview code from reading a stream forever. --- changelog.d/11784.bugfix | 1 + synapse/http/client.py | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) create mode 100644 changelog.d/11784.bugfix diff --git a/changelog.d/11784.bugfix b/changelog.d/11784.bugfix new file mode 100644 index 000000000..6569a8c29 --- /dev/null +++ b/changelog.d/11784.bugfix @@ -0,0 +1 @@ +Fix a long-standing bug that media streams could cause long-lived connections when generating URL previews. diff --git a/synapse/http/client.py b/synapse/http/client.py index ca33b45cb..743a7ffcb 100644 --- a/synapse/http/client.py +++ b/synapse/http/client.py @@ -731,15 +731,24 @@ class SimpleHttpClient: # straight back in again try: - length = await make_deferred_yieldable( - read_body_with_max_size(response, output_stream, max_size) - ) + d = read_body_with_max_size(response, output_stream, max_size) + + # Ensure that the body is not read forever. + d = timeout_deferred(d, 30, self.hs.get_reactor()) + + length = await make_deferred_yieldable(d) except BodyExceededMaxSize: raise SynapseError( HTTPStatus.BAD_GATEWAY, "Requested file is too large > %r bytes" % (max_size,), Codes.TOO_LARGE, ) + except defer.TimeoutError: + raise SynapseError( + HTTPStatus.BAD_GATEWAY, + "Requested file took too long to download", + Codes.TOO_LARGE, + ) except Exception as e: raise SynapseError( HTTPStatus.BAD_GATEWAY, ("Failed to download remote body: %s" % e)