In the Linux kernel, the following vulnerability has been resolved:
schhtb: make htbqlen_notify() idempotent
htbqlennotify() always deactivates the HTB class and in fact could trigger a warning if it is already deactivated. Therefore, it is not idempotent and not friendly to its callers, like fqcodeldequeue().
Let's make it idempotent to ease qdisctreereduce_backlog() callers' life.