Make sure size of response buffer is at least 6 bytes, or
we will underflow and pass large size_t to memcpy_fromio().
This was encountered while testing earlier version of
locality patchset.
Cc: stable@vger.kernel.org Fixes: 30fc8d138e912 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>