Syzkaller reports the leak [1]. It is reproducible.
The following patch fixes the leak. It was proposed by Takeshi Misawa and
tested by Syzbot.
In other places of the code the waitqueue is freed when its wait_ctr
becomes zero (see autofs_wait_release). So I think it is not actually
supposed that inside autofs_catatonic_mode wait_ctr cannot be decreased to
zero. Please correct me if I'm wrong.
Also, looking at the discussion [2] of the '[PATCH] autofs4: use wake_up()
instead of wake_up_interruptible', shouldn't wake_up_interruptible()
inside autofs_catatonic_mode() be replaced with wake_up()?