[PATCH v5 0/1] Fix and improve zcrypt reply message checks

[Harald Freudenberger <freude@linux.ibm.com>]

Fix and improve zcrypt reply messages checks of type 6 - CCA and EP11
- and type 50 - ICA.

Changelog:
v1: Initial version
v2: Sashiko complained about not checking offset1/count1 at all if
    count2 for an CCA type6 reply is given. And a check like this was
    in place before the rework. So now offset1/count1 is always
    checked and only if count2 is non zero offset2/count2 is
    additionally checked.
v3: Again Sashiko had some complains which let to a broader review of
    the reply processing functions. Especially the zcrypt_type50.c
    functions convert_type80() and convert_response() got slight but
    significant improvements - and also a mysterious BUG_ON has been
    removed.
v4: Again Sashiko had a complain about my restrictions are too
    tight. So now in convert_response_xcrb() the exact length
    verification is:
	case TYPE86_RSP_CODE:
		...
		if (reply->len < sizeof(struct type86_fmt2_msg) +
		    offsetof(struct CPRBX, cprb_ver_id) +
		    sizeof(msg->cprbx.cprb_ver_id))
			return -EINVAL;
		...
    thus postponing the final length check to the convert function
    (which does the job hopefully correct).
v5: Sashiko noticed that for two functions (convert_response_ica and
    convert_response_ep11_xcrb) the length check comes before the
    processing of short error replies - fixed.

Harald Freudenberger (1):
  s390/zcrypt: Fix and improve zcrypt reply message verification checks

 drivers/s390/crypto/zcrypt_msgtype50.c |  95 ++++++++----
 drivers/s390/crypto/zcrypt_msgtype6.c  | 202 ++++++++++++++++++-------
 2 files changed, 218 insertions(+), 79 deletions(-)

--
2.43.0