Merge branch 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fix from Tejun Heo:
 "If a delayed work is queued with NULL @wq, workqueue code explodes
  after the timer expires at which point it's difficult to tell who the
  culprit was.

  This actually happened and the offender was net/smc this time.

  Add an explicit sanity check for it in the queueing path"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq

kernel/workqueue.c

@@ -1507,6 +1507,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 	struct timer_list *timer = &dwork->timer;
 	struct work_struct *work = &dwork->work;
 
+	WARN_ON_ONCE(!wq);
 	WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
 		     timer->data != (unsigned long)dwork);
 	WARN_ON_ONCE(timer_pending(timer));