From 63ef79c25b5bbd356d04ef93d15693d8664c6141 Mon Sep 17 00:00:00 2001 From: Ingo Tuchscherer Date: Wed, 5 Feb 2014 12:29:57 +0100 Subject: s390/zcrypt: additional check to avoid overflow in msg-type 6 requests Signed-off-by: Ingo Tuchscherer Signed-off-by: Martin Schwidefsky --- drivers/s390/crypto/zcrypt_msgtype6.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'drivers/s390/crypto') diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c index dc542e0..0bc91e4 100644 --- a/drivers/s390/crypto/zcrypt_msgtype6.c +++ b/drivers/s390/crypto/zcrypt_msgtype6.c @@ -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)); -- cgit v1.1