linux-kernel - Re: [PATCH] workqueue: Put the pwq after detaching the rescuer from the pool

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] [day] [month] [year] [list]

Message-ID: <Z5PqUHHnvjp5VXmZ@slm.duckdns.org>
Date: Fri, 24 Jan 2025 09:30:24 -1000
From: Tejun Heo <tj@...nel.org>
To: Lai Jiangshan <jiangshanlai@...il.com>
Cc: linux-kernel@...r.kernel.org,
	Lai Jiangshan <jiangshan.ljs@...group.com>,
	cheung wall <zzqq0103.hey@...il.com>
Subject: Re: [PATCH] workqueue: Put the pwq after detaching the rescuer from
 the pool

On Thu, Jan 23, 2025 at 04:25:35PM +0800, Lai Jiangshan wrote:
> From: Lai Jiangshan <jiangshan.ljs@...group.com>
> 
> The commit 68f83057b913("workqueue: Reap workers via kthread_stop() and
> remove detach_completion") adds code to reap the normal workers but
> mistakenly does not handle the rescuer and also removes the code waiting
> for the rescuer in put_unbound_pool(), which caused a use-after-free bug
> reported by Cheung Wall.
> 
> To avoid the use-after-free bug, the pool’s reference must be held until
> the detachment is complete. Therefore, move the code that puts the pwq
> after detaching the rescuer from the pool.
> 
> Reported-by: cheung wall <zzqq0103.hey@...il.com>
> Cc: cheung wall <zzqq0103.hey@...il.com>
> Link: https://lore.kernel.org/lkml/CAKHoSAvP3iQW+GwmKzWjEAOoPvzeWeoMO0Gz7Pp3_4kxt-RMoA@mail.gmail.com/
> Fixes: 68f83057b913("workqueue: Reap workers via kthread_stop() and remove detach_completion")
> Signed-off-by: Lai Jiangshan <jiangshan.ljs@...group.com>

Applied to wq/for-6.14-fixes.

Thanks.

-- 
tejun