When all entries in an `LruCache` have a size of 0 according to the
provided `size_callback`, and `drop_from_cache` is called on a cache
node, the node would be unlinked from the LRU linked list but remain in
the cache dictionary. An assertion would be later be tripped due to the
inconsistency.
Avoid unintentionally calling `__len__` and use a strict `is None`
check instead when unwrapping the weak reference.
Part of https://github.com/matrix-org/synapse/issues/11300
Call stack:
- `_persist_events_and_state_updates` (added `use_negative_stream_ordering`)
- `_persist_events_txn`
- `_update_room_depths_txn` (added `update_room_forward_stream_ordering`)
- `_update_metadata_tables_txn`
- `_store_room_members_txn` (added `inhibit_local_membership_updates`)
Using keyword-only arguments (`*`) to reduce the mistakes from `backfilled` being left as a positional argument somewhere and being interpreted wrong by our new arguments.
Since e81fa92648, Synapse depends on
the use_float flag which has been introduced in ijson 3.1 and
is not available in 3.0. This is known to cause runtime errors
with send_join.
Signed-off-by: Daniel Molkentin <danimo@infra.run>
Co-authored-by: Daniel Molkentin <danimo@infra.run>
The previous fix for the ongoing event fetches counter
(8eec25a1d9) was both insufficient and
incorrect.
When the database is unreachable, `_do_fetch` never gets run and so
`_event_fetch_ongoing` is never decremented.
The previous fix also moved the `_event_fetch_ongoing` decrement outside
of the `_event_fetch_lock` which allowed race conditions to corrupt the
counter.
This change makes mypy complain if the constants are ever reassigned,
and, more usefully, makes mypy type them as `Literal`s instead of `str`s,
allowing code of the following form to pass mypy:
```py
def do_something(membership: Literal["join", "leave"], ...): ...
do_something(Membership.JOIN, ...)
```
* remove background update code related to deprecated config flag
* changelog entry
* update changelog
* Delete 11394.removal
Duplicate, wrong number
* add no-op background update and change newfragment so it will be consolidated with associated work
* remove unused code
* Remove code associated with deprecated flag from legacy docker dynamic config file
Co-authored-by: reivilibre <oliverw@matrix.org>
===========================
This release fixes a security issue in the media store, affecting all prior releases of Synapse. Server administrators are encouraged to update Synapse as soon as possible. We are not aware of these vulnerabilities being exploited in the wild.
Server administrators who are unable to update Synapse may use the workarounds described in the linked GitHub Security Advisory below.
Security advisory
-----------------
The following issue is fixed in 1.47.1.
- **[GHSA-3hfw-x7gx-437c](https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437c) / [CVE-2021-41281](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41281): Path traversal when downloading remote media.**
Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory, potentially outside the media store directory.
The last two directories and file name of the path are chosen randomly by Synapse and cannot be controlled by an attacker, which limits the impact.
Homeservers with the media repository disabled are unaffected. Homeservers configured with a federation whitelist are also unaffected.
Fixed by [91f2bd090](https://github.com/matrix-org/synapse/commit/91f2bd090).
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Merge tag 'v1.47.1'
Synapse 1.47.1 (2021-11-23)
===========================
This release fixes a security issue in the media store, affecting all prior releases of Synapse. Server administrators are encouraged to update Synapse as soon as possible. We are not aware of these vulnerabilities being exploited in the wild.
Server administrators who are unable to update Synapse may use the workarounds described in the linked GitHub Security Advisory below.
Security advisory
-----------------
The following issue is fixed in 1.47.1.
- **[GHSA-3hfw-x7gx-437c](https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437c) / [CVE-2021-41281](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41281): Path traversal when downloading remote media.**
Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory, potentially outside the media store directory.
The last two directories and file name of the path are chosen randomly by Synapse and cannot be controlled by an attacker, which limits the impact.
Homeservers with the media repository disabled are unaffected. Homeservers configured with a federation whitelist are also unaffected.
Fixed by [91f2bd090](https://github.com/matrix-org/synapse/commit/91f2bd090).
Instead of only known relation types. This also reworks the background
update for thread relations to crawl events and search for any relation
type, not just threaded relations.
