diff --git a/drivers/s390/cio/cio_inject.c b/drivers/s390/cio/cio_inject.c
index 8613fa937237..a2e771ebae8e 100644
--- a/drivers/s390/cio/cio_inject.c
+++ b/drivers/s390/cio/cio_inject.c
@@ -95,7 +95,7 @@ static ssize_t crw_inject_write(struct file *file, const char __user *buf,
 		return -EINVAL;
 	}
 
-	buffer = vmemdup_user(buf, lbuf);
+	buffer = memdup_user_nul(buf, lbuf);
 	if (IS_ERR(buffer))
 		return -ENOMEM;