v30 yanked?

[NotATether]

I just read the news that Bitcoin Core 30 and 30.1 were pulled from the downloads because they could delete some Satoshi-era wallets during migration, I guess of really old wallet.dat version.

How does this kind of bug manage to sneak into Core's codebase in the first place? You'd think that triage would make this sort if bug easily detectable once maintainers share it with each other.

And why is it still pinned on Bitcointalk? It should be yeeted out until 30.2 is released.

[Hypnotizer]

https://bitcointalk.org/index.php?topic=5570633.0

TryNinja posted about this yesterday's night in the bitcoin discussion board.

Edit-

Okayy, I thought you didn’t notice the other thread.

[NotATether]

https://bitcointalk.org/index.php?topic=5570633.0

TryNinja posted about this yesterday's night in the bitcoin discussion board.

But I'm interested in knowing more about the testing policy of Core and why it failed to catch this bug.

[Ambatman]

How does this kind of bug manage to sneak into Core's codebase in the first place? You'd think that triage would make this sort if bug easily detectable once maintainers share it with each other.

I believe this occurred because the condition for it was quite niche
Unnamed wallet
Custom wallet directory
Pruning enabled
Automatic migration (This was recently introduced)
Failure of the migration.

As can be seen below even the automatic backup was bypassed since the backup are stored
In the directory that is accidentally deleted.

It does.

The problem is that the backups are stored in a directory that is accidentally deleted by the bug as well. Obviously this is a major bug and it took a little while to figure out the scope of the issue.

[achow101]

But I'm interested in knowing more about the testing policy of Core and why it failed to catch this bug.

The tests were primarily focused on ensuring that everything was being migrated correctly, and that migration would not fail. As such, migration failures were both under-tested and difficult to test as making a wallet which failed to migrate was a non-trivial task.

I believe this occurred because the condition for it was quite niche
Unnamed wallet
Custom wallet directory
Pruning enabled
Automatic migration (This was recently introduced)
Failure of the migration.

Unnamed wallets are not that niche, Bitcoin Core made these by default for 12 years. We only stopped doing that 5 years ago, but it's still possible to create one on RPC, although I doubt people actually do that.

Custom wallet directory is not required, that was a red herring.

Wallets are not automatically migrated. Migration is something that requires explicit user action. If you don't choose to migrate the unnamed wallet, then nothing will happen.

[NeuroticFish]

Wallets are not automatically migrated. Migration is something that requires explicit user action. If you don't choose to migrate the unnamed wallet, then nothing will happen.

I think that this should be emphasized more (wherever the news on bitcoin core 30 and 30.1 are shown), else some people will get scared big time.

But I'm interested in knowing more about the testing policy of Core and why it failed to catch this bug.

Valid question, but I'll chip in with a bit more:
It's not the first time I see testing fails to catch an issue related to backward compatibility... with something really old.
Imho something more would be nice to have/to be added: a check/test to ensure that the migration of various generations of wallets works. Of course, it's only an idea, which the devs can take into account or can ignore.

[achow101]

Valid question, but I'll chip in with a bit more:
It's not the first time I see testing fails to catch an issue related to backward compatibility... with something really old.
Imho something more would be nice to have/to be added: a check/test to ensure that the migration of various generations of wallets works. Of course, it's only an idea, which the devs can take into account or can ignore.

It's not an issue that universally affects all old wallets. It entirely depends on what is in the wallet, and that can vary a lot depending on what the user did. Old wallets where the user did the bog standard and never imported anything are probably fine and won't hit this bug. Recently created legacy wallets where the user imported a bunch of random things might still hit this bug. Ultimately it's the fact that the space of possibilities is just so much larger than what we are able to test for.

[1440000bytes]

I just read the news that Bitcoin Core 30 and 30.1 were pulled from the downloads because they could delete some Satoshi-era wallets during migration

Not just legacy wallets. It deletes the wallets directory.

The version in the top download link on bitcointalk should be updated and the torrent link needs to be fixed.

[NotATether]

I believe this occurred because the condition for it was quite niche
Unnamed wallet
Custom wallet directory
Pruning enabled
Automatic migration (This was recently introduced)
Failure of the migration.

As can be seen below even the automatic backup was bypassed since the backup are stored
In the directory that is accidentally deleted.

I think automatic migration is a terrible idea. Wallet formats should be treated as legacy functionality that should always be supported just like how SQLite is backward-compatible with many obscure features in its latest version.

[joker_josue]

I think automatic migration is a terrible idea. Wallet formats should be treated as legacy functionality that should always be supported just like how SQLite is backward-compatible with many obscure features in its latest version.

Well, let's be realistic, it will always be difficult to guarantee eternal compatibility for very old versions.

Now, they can look to ensure an effective wallet conversion system so that those who had a wallet that was 10 years or older continue to have access to it - even if in a limited way.

But, like any bug, it's difficult to test all possibilities to mitigate this type of error. Either way, it will certainly be an error that won't be repeated, as it will be a scenario that becomes part of the testing in new versions (I hope).

[NotATether]

Well, let's be realistic, it will always be difficult to guarantee eternal compatibility for very old versions.

Now, they can look to ensure an effective wallet conversion system so that those who had a wallet that was 10 years or older continue to have access to it - even if in a limited way.

It doesn't really matter. Bitcoin Core as a software has much tighter operational requirements than almost any other software written, because it deals with money. A bug like this where people can lose access to their funds is fatal, whether or not somebody chose to make a backup copy of their wallet. That's why certain modules should basically be treated as legacy software, that should never be removed (unlike move-fast-and-break-things coins like Ethereum) just like banking software running on ancient languages, or Windows.

[joker_josue]

It doesn't really matter. Bitcoin Core as a software has much tighter operational requirements than almost any other software written, because it deals with money. A bug like this where people can lose access to their funds is fatal, whether or not somebody chose to make a backup copy of their wallet. That's why certain modules should basically be treated as legacy software, that should never be removed (unlike move-fast-and-break-things coins like Ethereum) just like banking software running on ancient languages, or Windows.

That is true.
That's why a lot of banking software is old and receives few updates, or it takes a long time to update. The risk of loss is very high, any change has to be very well defined and tested.


This may have been the first bug, so serious, that has occurred. Or am I mistaken?

[stwenhao]

This may have been the first bug, so serious, that has occurred. Or am I mistaken?

We had a lot of serious bugs: https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures

I guess things like Value overflow incident or OP_TRUE OP_RETURN were more serious than that. Because if it is only about wallet.dat file, then someone could have a backup, and solve all problems in this way. But in case of other bugs, they were exploitable globally, and having your node fixed was not enough, if other nodes were more vulnerable, and didn't enforce all rules properly.

[She shining]

According to an X user https://x.com/w_s_bitcoin/status/2008925702893011155?t=44ITRxATTJIk-yTuMlYzLA&s=19 The bug still exist in knots
likely true as knot usually just copy and change somethings https://github.com/bitcoinknots/bitcoin/blob/29.x-knots/src/wallet/dump.cpp#L289-L292. You can check out the github page or the X post.

[philipma1957]

I am running 28.0 for now with coins on a

bc1 Native segwit

I have a backup of the wallet

I usually wait a few months or more before I update the core.

[joker_josue]

I am running 28.0 for now with coins on a

bc1 Native segwit

I have a backup of the wallet

I usually wait a few months or more before I update the core.

I just checked, I'm still on version 25. That means I could still be experiencing this bug.
I haven't updated because of that, and I have several backups.

But this shows that many people may have older versions.

[NotATether]

According to an X user https://x.com/w_s_bitcoin/status/2008925702893011155?t=44ITRxATTJIk-yTuMlYzLA&s=19 The bug still exist in knots
likely true as knot usually just copy and change somethings https://github.com/bitcoinknots/bitcoin/blob/29.x-knots/src/wallet/dump.cpp#L289-L292. You can check out the github page or the X post.

And this is proof that Knots is even less secure than Core as far as wallets are concerned - it's literally just copy-paste with more likelihood that dangerous code gets through without adequate review.

(Yes, it is a reversal of opinion I had of Knots just a few months ago - at the end of the day, I just want my money to be safely stored.)

[Tinubu]

It doesn't really matter. Bitcoin Core as a software has much tighter operational requirements than almost any other software written, because it deals with money. A bug like this where people can lose access to their funds is fatal, whether or not somebody chose to make a backup copy of their wallet. That's why certain modules should basically be treated as legacy software, that should never be removed (unlike move-fast-and-break-things coins like Ethereum) just like banking software running on ancient languages, or Windows.

Really for me I think what changes everything is the 'irreversibility principle'...in the Traditional software, bugs can be very embarrassing...but in Bitcoin, they can be a serious problem (not just problems...they can make you lose your wealth forever) and this ain't conservatism..it means, you can't just click 'undo' when it comes to Bitcoin....

That's why removing old features can be very dangerous..you might lose your money forever (without recovery)..
So the entire value proposition of Bitcoin is in its 'boring stability' (moving slowly on purpose.. because it has to)...because Bitcoin can't expect people to have trust in them i they keep on changing and updating stuffs like these trendy tech softwares nowadays...

[Ambatman]

I just checked, I'm still on version 25. That means I could still be experiencing this bug.
I haven't updated because of that, and I have several backups.

But this shows that many people may have older versions.

No you or any older versions are not
The bug is only found in the current version of Core
Which introduced the removal of BDB from the code base.

BDB legacy wallets can no longer be created or loaded. They can be migrated
to the new descriptor wallet format. Refer to the migratewallet RPC for more
details.

Meanwhile a new version is now available for testing on Github
https://github.com/bitcoin/bitcoin/blob/v30.2rc1/doc/release-notes.md

[joker_josue]

I just checked, I'm still on version 25. That means I could still be experiencing this bug.
I haven't updated because of that, and I have several backups.

But this shows that many people may have older versions.

No you or any older versions are not
The bug is only found in the current version of Core
Which introduced the removal of BDB from the code base.

BDB legacy wallets can no longer be created or loaded. They can be migrated
to the new descriptor wallet format. Refer to the migratewallet RPC for more
details.

Meanwhile a new version is now available for testing on Github
https://github.com/bitcoin/bitcoin/blob/v30.2rc1/doc/release-notes.md

I didn't explain myself well. What I meant was that if I were to migrate now, I would be exposed to the problem.

If you had version 29 you wouldn't have this problem; the problem affects older versions, from version 25 and earlier.