Re: [PATCH] crypto: octeontx - use crypto_memneq() to check HMAC

[Herbert Xu]

On Sat, Aug 15, 2026 at 07:09:14PM +0200, David C.C.M. Gall wrote:
> validate_hmac_cipher_null() compares the computed and received HMAC
> with memcmp(), which short-circuits on the first differing byte and
> leaks tag-match length via timing. Use crypto_memneq() instead.
> 
> Because for cipher_null the validated payload is un-encrypted, this
> valid prefix leak allows for authenticated message forgery.
> 
> Assisted-by: gregkh_clanker_t1000
> Signed-off-by: David C.C.M. Gall <david.ccm.gall@xxxxxxxxxxxxxx>
> ---
>  drivers/crypto/marvell/octeontx/otx_cptvf_algs.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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