On Mon, Mar 22, 2021 at 08:45:22AM +0300, Dan Carpenter wrote:
> On Sun, Mar 21, 2021 at 10:07:48PM -0700, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@xxxxxxxxxx>
> >
> > crypto_stats_get() is a no-op when the kernel is compiled without
> > CONFIG_CRYPTO_STATS, so pairing it with crypto_alg_put() unconditionally
> > (as crypto_rng_reset() does) is wrong.
> >
>
> Presumably the intention was that _get() and _put() should always pair.
> It's really ugly and horrible that they don't. We could have
> predicted bug like this would happen and will continue to happen until
> the crypto_stats_get() is renamed.
>
Well, the crypto stats stuff has always been pretty broken, so I don't think
people have looked at it too closely. Currently crypto_stats_get() pairs with
one of the functions that tallies the statistics, such as
crypto_stats_rng_seed() or crypto_stats_aead_encrypt(). What change are you
suggesting, exactly? Maybe moving the conditional crypto_alg_put() into a new
function crypto_stats_put() and moving it into the callers? Or do you think the
functions should just be renamed to something like crypto_stats_begin() and
crypto_stats_end_{rng_seed,aead_encrypt}()?
Another issue is that a lot of operations (such as the rng one in question here)
don't actually need the get/put at all because they are never asynchronous. I
didn't aim to address that in my patch though...
- Eric
