Re: [PATCH v2 0/7] dm-integrity: asynchronous hash support

Mikulas Patocka
2025-09-11T15:59:06Z

On Thu, 11 Sep 2025, Ingo Franzki wrote:

> >> So, it looks like a dm-crypt bug.
> >>
> >> Please, revert my patches and run the same test on a clean 6.17.0-rc5 just
> >> to verify that the patches do not introduce the bug.
> >
> > With your patches reverted the combined mode fails the same way as with your patches.
> > So they did not introduce the bug.
>
> Mikulas, do you have any idea what could be causing this errors?
> Is it that dm-crypt is not properly dealing with async-only HMAC ciphers?
> Async-only encryption ciphers seem to work fine in dm-crypt, since LUKS with PAES (but no integrity) works fine, and PAES is an async-onky cipher.
> LUKS with sync-HMAC ciphers (e.g. clear key HMAC) also works fine, even in combination with PAES.

Yes, I think that it's a problem with async HMAC. The bug is probably
either in dm-crypt or in the crypto library.

Do you have some other (non-dm-crypt-related) workload that uses the
async authentication, so that we can determine whether the bug is in
dm-crypt or crypto?

Otherwise, would it be possible to give us a virtual machine on the
mainframe to debug this issue?

Mikulas