linux-kernel - Re: [syzbot] possible deadlock in worker

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:   Sun, 13 Feb 2022 17:44:25 -1000
From:   Tejun Heo <tj@...nel.org>
To:     Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
Cc:     Bart Van Assche <bvanassche@....org>,
        syzbot <syzbot+831661966588c802aae9@...kaller.appspotmail.com>,
        jgg@...pe.ca, linux-kernel@...r.kernel.org,
        linux-rdma@...r.kernel.org, syzkaller-bugs@...glegroups.com,
        Lai Jiangshan <jiangshanlai@...il.com>
Subject: Re: [syzbot] possible deadlock in worker_thread

Hello,

On Mon, Feb 14, 2022 at 10:08:00AM +0900, Tetsuo Handa wrote:
> +	destroy_workqueue(srp_tl_err_wq);
> 
> Then, we can call WARN_ON() if e.g. flush_workqueue() is called on system-wide workqueues.

Yeah, this is the right thing to do. It makes no sense at all to call
flush_workqueue() on the shared workqueues as the caller has no idea what
it's gonna end up waiting for. It was on my todo list a long while ago but
slipped through the crack. If anyone wanna take a stab at it (including
scrubbing the existing users, of course), please be my guest.

Thanks.

-- 
tejun