Re: [PATCH] crypto: api - fix reqsize handling for skciphers and aeads

[Herbert Xu <herbert@gondor.apana.org.au>]

On Tue, Oct 07, 2025 at 07:27:51PM +0530, T Pratham wrote:
> Commit afddce13ce81d ("crypto: api - Add reqsize to crypto_alg")
> introduced cra_reqsize field in crypto_alg struct to replace type
> specific reqsize fields. It looks like this was introduced specifically
> for ahash and acomp from the commit description as subsequent commits
> add necessary changes in these alg frameworks.
> 
> However, this is being recommended for use in all crypto algs [1]
> instead of setting reqsize using crypto_*_set_reqsize(). Using
> cra_reqsize in skcipher and aead algorithms, hence, causes memory
> corruptions and crashes as the underlying functions in the algorithm
> framework have not been updated to set the reqsize properly from
> cra_reqsize. [2]
> 
> Add proper set_reqsize calls in the skcipher and aead init functions to
> properly initialize reqsize for these algorithms in the framework.
> 
> [1]: https://lore.kernel.org/linux-crypto/aCL8BxpHr5OpT04k@gondor.apana.org.au/
> [2]: https://gist.github.com/Pratham-T/24247446f1faf4b7843e4014d5089f6b
> 
> Fixes: afddce13ce81d ("crypto: api - Add reqsize to crypto_alg")
> Signed-off-by: T Pratham <t-pratham@ti.com>
> ---
> 
> Found this while developing TI DTHEv2 crypto driver. I narrowed that
> these crashes in [2] are due to some upstream change and not my code as
> the same driver is working fine in our internal 6.12 LTS version (with
> daily CI builds not showing any regression from crypto subsystem). The
> *only* change is replacing crypto_skcipher_set_reqsize() with
> cra_reqsize in algorithms as this patch was introduced after 6.12.
> 
> Now, these crashes were not caught earlier because [3] split the
> in-kernel self-tests into two configs (CRYPTO_SELFTESTS and
> CRYPTO_SELFTESTS_FULL) which went unnoticed in my local development flow
> and the CRYPTO_SELFTESTS_FULL config was not enabled till recently. [2]
> shows after applying this patch, the driver passes all selftests
> succssfully with CRYPTO_SELFTESTS_FULL=y.
> 
> [3]: https://lore.kernel.org/linux-crypto/20250612174709.26990-1-ebiggers@kernel.org/
> ---
>  crypto/aead.c     | 1 +
>  crypto/skcipher.c | 2 ++
>  2 files changed, 3 insertions(+)

Thanks.  I've applied the skcipher part of your patch.

Please repost the AEAD part as a separate patch.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt