s390/zcrypt: additional check to avoid overflow in msg-type 6 requests

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Ingo Tuchscherer 2014-02-05 12:29:57 +01:00 committed by Martin Schwidefsky
parent 45f7fdc2ff
commit 63ef79c25b

View file

@ -311,7 +311,7 @@ static int XCRB_msg_to_type6CPRB_msgX(struct zcrypt_device *zdev,
} __packed * msg = ap_msg->message;
int rcblen = CEIL4(xcRB->request_control_blk_length);
int replylen;
int replylen, req_sumlen, resp_sumlen;
char *req_data = ap_msg->message + sizeof(struct type6_hdr) + rcblen;
char *function_code;
@ -321,12 +321,34 @@ static int XCRB_msg_to_type6CPRB_msgX(struct zcrypt_device *zdev,
xcRB->request_data_length;
if (ap_msg->length > MSGTYPE06_MAX_MSG_SIZE)
return -EINVAL;
/* Overflow check
sum must be greater (or equal) than the largest operand */
req_sumlen = CEIL4(xcRB->request_control_blk_length) +
xcRB->request_data_length;
if ((CEIL4(xcRB->request_control_blk_length) <=
xcRB->request_data_length) ?
(req_sumlen < xcRB->request_data_length) :
(req_sumlen < CEIL4(xcRB->request_control_blk_length))) {
return -EINVAL;
}
replylen = sizeof(struct type86_fmt2_msg) +
CEIL4(xcRB->reply_control_blk_length) +
xcRB->reply_data_length;
if (replylen > MSGTYPE06_MAX_MSG_SIZE)
return -EINVAL;
/* Overflow check
sum must be greater (or equal) than the largest operand */
resp_sumlen = CEIL4(xcRB->reply_control_blk_length) +
xcRB->reply_data_length;
if ((CEIL4(xcRB->reply_control_blk_length) <= xcRB->reply_data_length) ?
(resp_sumlen < xcRB->reply_data_length) :
(resp_sumlen < CEIL4(xcRB->reply_control_blk_length))) {
return -EINVAL;
}
/* prepare type6 header */
msg->hdr = static_type6_hdrX;
memcpy(msg->hdr.agent_id , &(xcRB->agent_ID), sizeof(xcRB->agent_ID));