diff --git a/drivers/staging/cxt1e1/linux.c b/drivers/staging/cxt1e1/linux.c
index 4a08e16e42f719470cd9a0b63de557d2b3ff704b..79206cb3fb946e785021607c7b12474bff9d73a5 100644
--- a/drivers/staging/cxt1e1/linux.c
+++ b/drivers/staging/cxt1e1/linux.c
@@ -866,6 +866,8 @@ c4_ioctl (struct net_device *ndev, struct ifreq *ifr, int cmd)
             _IOC_SIZE (iocmd));
 #endif
     iolen = _IOC_SIZE (iocmd);
+    if (iolen > sizeof(arg))
+        return -EFAULT;
     data = ifr->ifr_data + sizeof (iocmd);
     if (copy_from_user (&arg, data, iolen))
         return -EFAULT;