nvme-auth: use crypto_memneq for DH-HMAC-CHAP response comparison

DH-HMAC-CHAP authentication compares HMAC response digests with memcmp().
Standard memcmp() may stop at the first differing byte, which can leak
timing information to a remote attacker and allow incremental recovery
of the expected digest.

Use crypto_memneq() for constant-time comparison on both the host path
that validates the controller Success1 response and the target path that
validates the host Reply digest.  Other memcmp() uses in the NVMe auth
code (e.g. fixed string prefix checks) are not security-sensitive and
are left unchanged.

Signed-off-by: Xixin Liu <liuxixin@kylinos.cn>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

0 files changed, 0 insertions, 0 deletions