--- zzzz-none-000/linux-4.4.60/drivers/usb/gadget/configfs.c	2017-04-08 07:53:53.000000000 +0000
+++ dragonfly-4020-701/linux-4.4.60/drivers/usb/gadget/configfs.c	2018-11-08 13:36:17.000000000 +0000
@@ -109,21 +109,28 @@
 	struct list_head list;
 };
 
+#define MAX_USB_STRING_LEN	126
+#define MAX_USB_STRING_WITH_NULL_LEN	(MAX_USB_STRING_LEN+1)
+
 static int usb_string_copy(const char *s, char **s_copy)
 {
 	int ret;
 	char *str;
 	char *copy = *s_copy;
 	ret = strlen(s);
-	if (ret > 126)
+	if (ret > MAX_USB_STRING_LEN)
 		return -EOVERFLOW;
 
-	str = kstrdup(s, GFP_KERNEL);
-	if (!str)
-		return -ENOMEM;
+	if (copy) {
+		str = copy;
+	} else {
+		str = kmalloc(MAX_USB_STRING_WITH_NULL_LEN, GFP_KERNEL);
+		if (!str)
+			return -ENOMEM;
+	}
+	strncpy(str, s, MAX_USB_STRING_WITH_NULL_LEN);
 	if (str[ret - 1] == '\n')
 		str[ret - 1] = '\0';
-	kfree(copy);
 	*s_copy = str;
 	return 0;
 }