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authorHeiko Carstens <heiko.carstens@de.ibm.com>2010-01-13 20:44:43 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-01-13 20:44:46 +0100
commit0648f5659e2d51659bd8f42ff30f456775c3c12d (patch)
tree1af4ccaa13998e773ff06969a8039ecc35e76785 /drivers/s390/crypto
parent94e587f61ef5da3b4da40289cdb7e9a62d455313 (diff)
downloadop-kernel-dev-0648f5659e2d51659bd8f42ff30f456775c3c12d.zip
op-kernel-dev-0648f5659e2d51659bd8f42ff30f456775c3c12d.tar.gz
[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>
Diffstat (limited to 'drivers/s390/crypto')
-rw-r--r--drivers/s390/crypto/zcrypt_api.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 0d4d18b..c68be24 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) ||
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