bug: collision in v12 room IDs when creating them fast #2424

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opened 2026-10-28 22:13:54 +00:00 by mkende · 3 comments

mkende commented

2026-10-28 22:13:54 +00:00

What is the bug?

I’m running a mautrix bridge with a continuwuity server and I noticed that several chats from the remote network ended up in the same matrix room.

From the server logs what happened is that the bridge bot created the 2 rooms at the same instant (up to the milliseconds), so they got the same ID which is minted from the initial event (which contains only the timestamp and the bot account name). And nothing in Continuwuity synchronizes the two create paths, which end up with the same room ID.

I guess the bridge could just create the events slower to fix this. But, if my statement above is correct, this is arguably a bug in Continuwuity.

Steps to reproduce

not easy to reproduce. I suppose that by using a fast bot that create rooms this can be observed. Although the initial room creation of the "mautrix-meta" bridge hit that bug a couple of times so this is probably reproducible with that too.

Server name and version

a personnal server, running v26.9.1 046074b

Additional context

No response

### What is the bug? I’m running a mautrix bridge with a continuwuity server and I noticed that several chats from the remote network ended up in the same matrix room. From the server logs what happened is that the bridge bot created the 2 rooms at the same instant (up to the milliseconds), so they got the same ID which is minted from the initial event (which contains only the timestamp and the bot account name). And nothing in Continuwuity synchronizes the two create paths, which end up with the same room ID. I guess the bridge could just create the events slower to fix this. But, if my statement above is correct, this is arguably a bug in Continuwuity. ### Steps to reproduce not easy to reproduce. I suppose that by using a fast bot that create rooms this can be observed. Although the initial room creation of the "mautrix-meta" bridge hit that bug a couple of times so this is probably reproducible with that too. ### Server name and version a personnal server, running v26.9.1 046074b ### Additional context _No response_

mkende added the

Bug

Status

Needs Investigation

labels

2026-10-28 22:13:54 +00:00

eleboucher referenced this issue from a pull request that will close it,

2026-10-31 08:55:57 +00:00

fix: Avoid v12 room ID collisions when creating rooms concurrently #2433

Jade referenced this issue from a commit

2026-11-03 09:52:44 +00:00

fix: Avoid v12 room ID collisions when creating rooms concurrently

Jade closed this issue

2026-11-03 09:52:44 +00:00

mkende commented

2026-11-04 20:54:25 +00:00

Author

Thanks @Jade for the fix!

Henry-Hiles commented

2026-11-04 20:59:04 +00:00

Member

@mkende wrote in #2424 (comment):

Thanks @Jade for the fix!

Give thanks to @eleboucher too, he fixed it, Jade just reviewed/merged :)

@mkende wrote in https://forgejo.ellis.link/continuwuation/continuwuity/issues/2424#issuecomment-38784: > Thanks @Jade for the fix! Give thanks to @eleboucher too, he fixed it, Jade just reviewed/merged :)

mkende commented

2026-11-04 21:01:33 +00:00

Author