[PATCH 5.4 067/222] s390/zcrypt: Fix CCA cipher key gen with clear key value function

Greg Kroah-Hartman
2020-01-22T13:19:57Z

From: Harald Freudenberger <freude@linux.ibm.com>

commit 94dd3bada53ee77b80d0aeee5571eeb83654d156 upstream.

Regression tests showed that the CCA cipher key function which
generates an CCA cipher key with given clear key value does not work
correctly. At parsing the reply CPRB two limits are wrong calculated
resulting in rejecting the reply as invalid with s390dbf message
"_ip_cprb_helper reply with invalid or unknown key block".

Fixes: f2bbc96e7cfa ("s390/pkey: add CCA AES cipher key support")
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/s390/crypto/zcrypt_ccamisc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/s390/crypto/zcrypt_ccamisc.c
+++ b/drivers/s390/crypto/zcrypt_ccamisc.c
@@ -1037,8 +1037,8 @@ static int _ip_cprb_helper(u16 cardnr, u
prepparm = (struct iprepparm *) prepcblk->rpl_parmb;

/* do some plausibility checks on the key block */
- if (prepparm->kb.len < 120 + 5 * sizeof(uint16_t) ||
- prepparm->kb.len > 136 + 5 * sizeof(uint16_t)) {
+ if (prepparm->kb.len < 120 + 3 * sizeof(uint16_t) ||
+ prepparm->kb.len > 136 + 3 * sizeof(uint16_t)) {
DEBUG_ERR("%s reply with invalid or unknown key block\n",
__func__);
rc = -EIO;