[PATCH] USB: fix oops in io_edgeport.c driver

This fixes https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=128916Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/serial/io_edgeport.c

@@ -2797,9 +2797,12 @@ static void change_port_settings (struct edgeport_port *edge_port, struct termio
 static void unicode_to_ascii (char *string, __le16 *unicode, int unicode_size)
 {
 	int i;
-	for (i = 0; i < unicode_size; ++i) {
+
+	if (unicode_size <= 0)
+		return;
+
+	for (i = 0; i < unicode_size; ++i)
 		string[i] = (char)(le16_to_cpu(unicode[i]));
-	}
 	string[unicode_size] = 0x00;
 }