diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2010-01-13 20:44:43 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2010-01-13 20:44:46 +0100 |
| commit | 0648f5659e2d51659bd8f42ff30f456775c3c12d (patch) | |
| tree | 1af4ccaa13998e773ff06969a8039ecc35e76785 | |
| parent | 94e587f61ef5da3b4da40289cdb7e9a62d455313 (diff) | |
[S390] zcrypt: add sanity check before copy_from_user()
It's not obvious that copy_from_user() is called with a sane length
parameter here. Even though it currently seems to be correct better
add a check to prevent stack corruption / exploits.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | drivers/s390/crypto/zcrypt_api.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 0d4d18bdd45c..c68be24e27d9 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -393,10 +393,12 @@ static long zcrypt_rsa_crt(struct ica_rsa_modexpo_crt *crt) * u_mult_inv > 128 bytes. */ if (copied == 0) { - int len; + unsigned int len; spin_unlock_bh(&zcrypt_device_lock); /* len is max 256 / 2 - 120 = 8 */ len = crt->inputdatalength / 2 - 120; + if (len > sizeof(z1)) + return -EFAULT; z1 = z2 = z3 = 0; if (copy_from_user(&z1, crt->np_prime, len) || copy_from_user(&z2, crt->bp_key, len) || |