diff options
| author | Harald Freudenberger <freude@linux.ibm.com> | 2018-06-27 09:50:43 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-07-02 11:24:55 +0200 |
| commit | 1fee96264a718fc5a2a94a09d5c7e2915a1c76b2 (patch) | |
| tree | 7a489dfd2bb1be1eb443b239410eb901689eca58 /drivers/s390/crypto/zcrypt_msgtype6.c | |
| parent | ad82a928eb58471adb2dec2001f5fbe57e5ee4b5 (diff) | |
s390/zcrypt: add copy_from_user length plausibility checks
There have been identified some places in the zcrypt
device driver where copy_from_user() is called but the
length value is not explicitly checked.
So now some plausibility checks and comments have been
introduced there.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/crypto/zcrypt_msgtype6.c')
| -rw-r--r-- | drivers/s390/crypto/zcrypt_msgtype6.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c index 97d4bacbc442..e70ae078c86b 100644 --- a/drivers/s390/crypto/zcrypt_msgtype6.c +++ b/drivers/s390/crypto/zcrypt_msgtype6.c @@ -246,7 +246,7 @@ int speed_idx_ep11(int req_type) * @ap_msg: pointer to AP message * @mex: pointer to user input data * - * Returns 0 on success or -EFAULT. + * Returns 0 on success or negative errno value. */ static int ICAMEX_msg_to_type6MEX_msgX(struct zcrypt_queue *zq, struct ap_message *ap_msg, @@ -272,6 +272,14 @@ static int ICAMEX_msg_to_type6MEX_msgX(struct zcrypt_queue *zq, } __packed * msg = ap_msg->message; int size; + /* + * The inputdatalength was a selection criteria in the dispatching + * function zcrypt_rsa_modexpo(). However, make sure the following + * copy_from_user() never exceeds the allocated buffer space. + */ + if (WARN_ON_ONCE(mex->inputdatalength > PAGE_SIZE)) + return -EINVAL; + /* VUD.ciphertext */ msg->length = mex->inputdatalength + 2; if (copy_from_user(msg->text, mex->inputdata, mex->inputdatalength)) @@ -307,7 +315,7 @@ static int ICAMEX_msg_to_type6MEX_msgX(struct zcrypt_queue *zq, * @ap_msg: pointer to AP message * @crt: pointer to user input data * - * Returns 0 on success or -EFAULT. + * Returns 0 on success or negative errno value. */ static int ICACRT_msg_to_type6CRT_msgX(struct zcrypt_queue *zq, struct ap_message *ap_msg, @@ -334,6 +342,14 @@ static int ICACRT_msg_to_type6CRT_msgX(struct zcrypt_queue *zq, } __packed * msg = ap_msg->message; int size; + /* + * The inputdatalength was a selection criteria in the dispatching + * function zcrypt_rsa_crt(). However, make sure the following + * copy_from_user() never exceeds the allocated buffer space. + */ + if (WARN_ON_ONCE(crt->inputdatalength > PAGE_SIZE)) + return -EINVAL; + /* VUD.ciphertext */ msg->length = crt->inputdatalength + 2; if (copy_from_user(msg->text, crt->inputdata, crt->inputdatalength)) |