mei: mei_write correct checks for copy_from_user

1. return -EFUALT when copy_from_user fails
2. display error message on failure in error level
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/main.c

@@ -404,8 +404,11 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 		goto out;
 
 	rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
-	if (rets)
+	if (rets) {
+		dev_err(&dev->pdev->dev, "failed to copy data from userland\n");
+		rets = -EFAULT;
 		goto out;
+	}
 
 	if (cl == &dev->iamthif_cl) {
 		rets = mei_amthif_write(dev, write_cb);
@@ -567,7 +570,7 @@ static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 	dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
 	if (copy_from_user(connect_data, (char __user *)data,
 				sizeof(struct mei_connect_client_data))) {
-		dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
+		dev_err(&dev->pdev->dev, "failed to copy data from userland\n");
 		rets = -EFAULT;
 		goto out;
 	}