linux-kernel - Re: [PATCH 0/1] autofs: fix memory leak of waitqueues in autofs_catatonic

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 13 Feb 2023 09:25:59 +0800
From:   Ian Kent <raven@...maw.net>
To:     Fedor Pchelkin <pchelkin@...ras.ru>
Cc:     Matthew Wilcox <willy@...radead.org>,
        Andrei Vagin <avagin@...il.com>,
        Takeshi Misawa <jeliantsurux@...il.com>,
        autofs@...r.kernel.org, linux-kernel@...r.kernel.org,
        Alexey Khoroshilov <khoroshilov@...ras.ru>,
        lvc-project@...uxtesting.org
Subject: Re: [PATCH 0/1] autofs: fix memory leak of waitqueues in
 autofs_catatonic_mode

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