Weakness in auth chain indexing allows DoS from remote room members
through disk fill and high CPU usage.
A remote Matrix user with malicious intent, sharing a room with Synapse
instances before 1.104.1, can dispatch specially crafted events to
exploit a weakness in how the auth chain cover index is calculated. This
can induce high CPU consumption and accumulate excessive data in the
database of such instances, resulting in a denial of service.
Servers in private federations, or those that do not federate, are not
affected.
This PR fixes a very, very niche edge-case, but I've got some more work
coming which will otherwise make the problem worse.
The bug happens when the syncing user leaves a room, and has a sync
filter which includes "left" rooms, but sets the timeline limit to 0. In
that case, the state returned in the `state` section is calculated
incorrectly.
The fix is to pass a token corresponding to the point that the user
leaves the room through to `compute_state_delta`.
When running unit tests, we patch the database connection pool so that
it runs queries "synchronously". This is ok, except that if any queries
are launched before we do the patching, those queries get left in limbo
and never complete.
To fix this, let's change the way we do the switcheroo, by patching out
the method which creates the connection pool in the first place.
When a lot of locks are waiting for a single lock, notifying all locks
independently with `call_later` on each release is really costly and
incurs some kind of async contention, where the CPU is spinning a lot
for not much.
The included test is taking around 30s before the change, and 0.5s
after.
It was found following failing tests with
https://github.com/element-hq/synapse/pull/16827.
We do this by adding support to the LRU cache for "extra indices" based
on the cached value. This allows us to efficiently map from room ID to
the cached events and only invalidate those.
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
Prior to this PR, if a request to create a public (public as in
published to the rooms directory) room violated the room list
publication rules set in the
[config](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#room_list_publication_rules),
the request to create the room was denied and the room was not created.
This PR changes the behavior such that when a request to create a room
published to the directory violates room list publication rules, the
room is still created but the room is not published to the directory.
The idea here being that the directory server shouldn't advertise rooms
to a requesting server is the requesting server would not be allowed to
join or participate in the room.
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Original commit schedule, with full messages:
<ol>
<li>
Pass `from_federation_origin` down into room list retrieval code
</li>
<li>
Don't cache /publicRooms response for inbound federated requests
</li>
<li>
fixup! Don't cache /publicRooms response for inbound federated requests
</li>
<li>
Cap the number of /publicRooms entries to 100
</li>
<li>
Simplify code now that you can't request unlimited rooms
</li>
<li>
Filter out rooms from federated requests that don't have the correct ACL
</li>
<li>
Request a handful more when filtering ACLs so that we can try to avoid
shortchanging the requester
</li>
</ol>
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
There are a couple of things we need to be careful of here:
1. The current python code does no validation when loading from the DB,
so we need to be careful to ignore such errors (at least on jki.re there
are some old events with internal metadata fields of the wrong type).
2. We want to be memory efficient, as we often have many hundreds of
thousands of events in the cache at a time.
---------
Co-authored-by: Quentin Gliech <quenting@element.io>
Previously, the response status of `HTMLResource` was hardcoded as
`200`. However, for proper redirection after the user verifies their
email, we require the status to be `302`. This PR addresses that issue
by using `code` as response status.
Closes:
- https://github.com/matrix-org/synapse/issues/10397
- #10397
An administrator should know whether he wants to set a password or not.
There are many uses cases where a blank password is required.
- Use of only some users with SSO.
- Use of bots with password, users with SSO
This reverts two commits:
0bb8e418a4
"Fix postgres schema after dropping old tables (#16730)"
and
51e4e35653
"Add a Postgres `REPLICA IDENTITY` to tables that do not have an implicit one. This should allow use of Postgres logical replication. (take 2, now with no added deadlocks!) (#16658)"
and also amends the changelog.
* Add `ALTER TABLE ... REPLICA IDENTITY ...` for individual tables
We can't combine them into one file as it makes it likely to hit a deadlock
if Synapse is running, as it only takes one other transaction to access two
tables in a different order to the schema delta.
* Add notes
* Newsfile
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
* Re-introduce REPLICA IDENTITY test
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
Implement MSC3860 to follow redirects for federated media downloads.
Note that the Client-Server API doesn't support this (yet) since the media
repository in Synapse doesn't have a way of supporting redirects.
* Describe `insert_client_ip`
* Pull out client_ips and MAU tracking to BaseAuth
* Define HAS_AUTHLIB once in tests
sick of copypasting
* Track ips and token usage when delegating auth
* Test that we track MAU and user_ips
* Don't track `__oidc_admin`
If a worker reconnects to Redis we send out the current positions of all our streams. However, if we're also trying to send out a backlog of RDATA at the same time then we can end up sending a `POSITION` with the current token *before* we've sent all the RDATA before the current token.
This doesn't cause actual bugs as the receiving servers see the POSITION, fetch the relevant rows from the DB, and then ignore the old RDATA as they come in. However, this is inefficient so it'd be better if we didn't send out-of-order positions
* Fix the CI query that did not detect all cases of missing primary keys
* Add more missing REPLICA IDENTITY entries
* Newsfile
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
* Add Postgres replica identities to tables that don't have an implicit one
Fixes#16224
* Newsfile
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
* Move the delta to version 83 as we missed the boat for 82
* Add a test that all tables have a REPLICA IDENTITY
* Extend the test to include when indices are deleted
* isort
* black
* Fully qualify `oid` as it is a 'hidden attribute' in Postgres 11
* Update tests/storage/test_database.py
Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
* Add missed tables
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
If simple_{insert,upsert,update}_many_txn is called without any data
to modify then return instead of executing the query.
This matches the behavior of simple_{select,delete}_many_txn.
This is mostly useful for federated rooms where some users
would get stuck in the invite or knock state when the room
was purged from their homeserver.
This adds a module API which allows a module to update a user's
presence state/status message. This is useful for controlling presence
from an external system.
To fully control presence from the module the presence.enabled config
parameter gains a new state of "untracked" which disables internal tracking
of presence changes via user actions, etc. Only updates from the module will
be persisted and sent down sync properly).
Twisted trunk makes a change to the `TLSMemoryBIOFactory` where
the underlying protocol is changed from `TLSMemoryBIOProtocol` to
`BufferingTLSTransport` to improve performance of TLS code (see
https://github.com/twisted/twisted/issues/11989).
In order to properly hook this code up in tests we need to pass the test
reactor's clock into `TLSMemoryBIOFactory` to avoid the global (trial)
reactor being used by default.
Twisted does something similar internally for tests:
157cd8e659/src/twisted/web/test/test_agent.py (L871-L874)
This reverts commit 5fe76b9434.
I think I had this accidentally commited on my local develop branch, and
so it accidentally got merged into upstream develop.
This should re-land with corrections in #16504.
* Fix bug where a new writer advances their token too quickly
When starting a new writer (for e.g. persisting events), the
`MultiWriterIdGenerator` doesn't have a minimum token for it as there
are no rows matching that new writer in the DB.
This results in the the first stream ID it acquired being announced as
persisted *before* it actually finishes persisting, if another writer
gets and persists a subsequent stream ID. This is due to the logic of
setting the minimum persisted position to the minimum known position of
across all writers, and the new writer starts off not being considered.
* Fix sending out POSITIONs when our token advances without update
Broke in #14820
* For replication HTTP requests, only wait for minimal position
Synapse was incorrectly implemented with a knock_state_events
property on some APIs (instead of knock_room_state). This was
correct in Synapse 1.70.0, but *both* fields were sent to also be
compatible with Synapse versions expecting the wrong field.
Enough time has passed that only the correct field needs to be
included/handled.
This converts the media servlet URLs in the same way as
(most) of the rest of Synapse. This will give more flexibility
in the versions each endpoint exists under.
Melvyn Laïly