freebsd security - Aug 2018 - Corruption seen from OCF after applying FreeBSD-SA-18:07.lazyfpu.

We have a product that uses OCF to encrypt disk blocks. Since applying the
FreeBSD-SA-18:07.lazyfpu patch we are seeing occasional corruption. The amount
of corrupted data is always less than the request size and is always a multiple
of the AES block size. Retrying the operation always succeeds leading to the
conclusion that this seems to be a locking issue. The only thing so far that we
can come up with is that this seems to result from either the OCF layer itself
or the AES-NI driver below it. Looking for suggestions about where to proceed
next.

On Mon, Aug 20, 2018 at 08:07:04PM -0700, bowwave wrote:
> 
> We have a product that uses OCF to encrypt disk blocks. Since
> applying the FreeBSD-SA-18:07.lazyfpu patch we are seeing occasional
> corruption. The amount of corrupted data is always less than the
> request size and is always a multiple of the AES block size. Retrying
> the operation always succeeds leading to the conclusion that this
> seems to be a locking issue. The only thing so far that we can come
> up with is that this seems to result from either the OCF layer itself
> or the AES-NI driver below it. Looking for suggestions about where to
> proceed next.
>
Most likely you need r336683, merged as r336963 to stable/11 and
r337245 to stable/10.  Some day there will be an EN.