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From: Tejun Heo <tj@kernel.org>
To: Sven Van Asbroeck <thesven73@gmail.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-kernel@vger.kernel.org, Sebastian Reichel <sre@kernel.org>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [RFC v1 1/3] workqueue: Add resource-managed version of INIT_[DELAYED_]WORK()
Date: Fri, 8 Feb 2019 09:06:56 -0800	[thread overview]
Message-ID: <20190208170656.GL50184@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <20190204220952.30761-2-TheSven73@googlemail.com>

On Mon, Feb 04, 2019 at 05:09:50PM -0500, Sven Van Asbroeck wrote:
> In modules which extensively use devm_ resource management, it is often
> easy to overlook (delayed) work that is left pending or running after the
> module is unloaded. This could introduce user-after-free issues.
> 
> Nudge kernel developers into 'doing the right thing' by introducing a
> resource-managed version of INIT_[DELAYED_]WORK(). This can be used as
> an elegant way to ensure that work is not left pending or running after
> its dependencies are released.
> 
> Functions introduced in workqueue.h :
> - devm_init_work()
> - devm_init_delayed_work()

I don't object to the basic idea but cancel_[delayed_]work_sync()
works iff queueing is disabled already, so there can be situations
where this can lead to surprising / subtle failures.  Given that, it
*might* not be a bad idea to keep this explicit unless there is a way
to reliably block future queueing.

Thanks.

-- 
tejun

  reply	other threads:[~2019-02-08 17:07 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-04 22:09 [RFC v1 0/3] Address potential user-after-free on module unload Sven Van Asbroeck
2019-02-04 22:09 ` [RFC v1 1/3] workqueue: Add resource-managed version of INIT_[DELAYED_]WORK() Sven Van Asbroeck
2019-02-08 17:06   ` Tejun Heo [this message]
2019-02-08 18:15     ` Sven Van Asbroeck
2019-02-04 22:09 ` [RFC v1 2/3] max17042_battery: fix potential user-after-free on module unload Sven Van Asbroeck
2019-02-05  8:27   ` Dmitry Torokhov
2019-02-05 14:27     ` Sven Van Asbroeck
2019-02-05 17:21       ` Sebastian Reichel
2019-02-04 22:09 ` [RFC v1 3/3] cap11xx: " Sven Van Asbroeck
2019-02-05  8:18   ` Dmitry Torokhov
2019-02-05  8:34     ` Dmitry Torokhov
2019-02-05 21:24     ` Jacek Anaszewski
2019-02-05 21:43       ` Dmitry Torokhov
2019-02-05 22:03         ` Sven Van Asbroeck
2019-02-05 14:57 ` [RFC v1 0/3] Address " Kees Cook
2019-02-05 15:22   ` Sven Van Asbroeck
2019-02-05 18:43     ` Greg KH
2019-02-05 19:12       ` Sven Van Asbroeck
2019-02-06 16:46         ` Greg KH
2019-02-06 17:30           ` Dmitry Torokhov
2019-02-06 17:49             ` Sven Van Asbroeck
2019-02-08  6:51             ` Greg KH
2019-02-05 18:42   ` Greg KH
2019-02-07 21:49   ` Sven Van Asbroeck
2019-02-07 22:20     ` Dmitry Torokhov
2019-02-07 22:27       ` Sven Van Asbroeck
2019-02-07 22:32       ` Sven Van Asbroeck
2019-02-07 22:48         ` Dmitry Torokhov
2019-02-08  4:30         ` Miguel Ojeda
2019-02-10 18:05           ` Sven Van Asbroeck
2019-02-14  1:11             ` Miguel Ojeda
2019-02-14 15:23               ` Sven Van Asbroeck
     [not found]     ` <CAGngYiXcogd69n-MvBD1n5ZJpBzqCau8UOfLMgXEXLnAev=srw@mail.gmail.com>
     [not found]       ` <alpine.DEB.2.21.1902080745480.4201@hadrien>
2019-02-14 17:52         ` Fwd: " Sven Van Asbroeck

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