On Tue, Jun 30, 2020 at 02:19:04PM +0200, Ard Biesheuvel wrote: > Even though the picoxcell driver implements asynchronous versions of > ecb(aes) and cbc(aes), the fallbacks it allocates are required to be > synchronous. Given that SIMD based software implementations are usually > asynchronous as well, even though they rarely complete asynchronously > (this typically only happens in cases where the request was made from > softirq context, while SIMD was already in use in the task context that > it interrupted), these implementations are disregarded, and either the > generic C version or another table based version implemented in assembler > is selected instead. > > Since falling back to synchronous AES is not only a performance issue, but > potentially a security issue as well (due to the fact that table based AES > is not time invariant), let's fix this, by allocating an ordinary skcipher > as the fallback, and invoke it with the completion routine that was given > to the outer request. > > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Thanks Ard! Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxxx>
