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

[T Pratham <t-pratham@ti.com>]

On 08/10/25 13:45, Herbert Xu wrote:
> 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,

Sent.
https://lore.kernel.org/linux-crypto/20251008100117.808195-1-t-pratham@ti.com/T/#u

-- 
Regards
T Pratham <t-pratham@ti.com>