From: Greg KH <gregkh@linuxfoundation.org>
To: Sven Van Asbroeck <thesven73@gmail.com>
Cc: Kees Cook <keescook@chromium.org>, Tejun Heo <tj@kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Sebastian Reichel <sre@kernel.org>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>
Subject: Re: [RFC v1 0/3] Address potential user-after-free on module unload
Date: Wed, 6 Feb 2019 17:46:57 +0100 [thread overview]
Message-ID: <20190206164657.GC8466@kroah.com> (raw)
In-Reply-To: <CAGngYiUMuM_ZxHKVWRihDHZcMncvTwR6Sz1zGNJLrGpyhhT1uQ@mail.gmail.com>
On Tue, Feb 05, 2019 at 02:12:31PM -0500, Sven Van Asbroeck wrote:
> On Tue, Feb 5, 2019 at 1:43 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> >
> > It really should happen when the device is removed (if it is a driver
> > that binds to a device.)
>
> Absolutely. That's why I'm advocating adding a devm_init_work(),
> which will take care of this automatically.
>
> But it's of course not universally applicable. Not all drivers use devm.
Ick, no, watch out for devm() calls. Odds are this is _NOT_ what you
want to do for a device. Remember when devm calls get freed (hint, not
at driver unbind/unload, but at device structure removal.
By creating a work queue, you are suddenly tying module code to a device
memory structure lifespan, both of which are totally independant.
It's the same issue with the devm irq call, that has been nothing but a
nightmare as everyone gets it wrong. Try to learn from our past
mistakes please :)
thanks,
greg k-h
next prev parent reply other threads:[~2019-02-06 16:47 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
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 [this message]
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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