Re: [PATCH 0/1] autofs: fix memory leak of waitqueues in autofs_catatonic_mode

From: Ian Kent
Date: Sun Feb 12 2023 - 20:26:24 EST


On 12/2/23 03:59, Fedor Pchelkin wrote:
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.

Clearly there's a problem here but I'll need to think about what's going

a bit more myself.



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()?

Yes, I think so but that also deserves a bit of thought.


Ian