[PATCH] mpt3sas: downgrade full copy_from_user to access_ok check

[Meng Xu <mengxu.gatech@xxxxxxxxx>]

Since right after the user copy, we are going to
memset(&karg, 0, sizeof(karg)), I guess an access_ok check is enough?

Signed-off-by: Meng Xu <mengxu.gatech@xxxxxxxxx>
---
 drivers/scsi/mpt3sas/mpt3sas_ctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index bdffb69..b363d2d 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -1065,7 +1065,7 @@ _ctl_getiocinfo(struct MPT3SAS_ADAPTER *ioc, void __user *arg)
 {
 	struct mpt3_ioctl_iocinfo karg;
 
-	if (copy_from_user(&karg, arg, sizeof(karg))) {
+	if (!access_ok(VERIFY_READ, arg, sizeof(karg))) {
 		pr_err("failure at %s:%d/%s()!\n",
 		    __FILE__, __LINE__, __func__);
 		return -EFAULT;
-- 
2.7.4