Linux Input/HID development
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From: "Rafael Passos" <rafael@rcpassos.me>
To: "David Rheinsberg" <david@readahead.eu>,
	"Rafael Passos" <rafael@rcpassos.me>,
	"Jiri Kosina" <jikos@kernel.org>,
	"Benjamin Tissoires" <bentiss@kernel.org>
Cc: "Shuah Khan" <skhan@linuxfoundation.org>,
	"Brigham Campbell" <me@brighamcampbell.com>,
	"Jori Koolstra" <jkoolstra@xs4all.nl>,
	<linux-input@vger.kernel.org>
Subject: Re: [PATCH v3 4/4] HID: wiimote: fix uaf when hid events are handled during destroy
Date: Mon, 17 Aug 2026 17:20:46 -0300	[thread overview]
Message-ID: <DKRHXTB2RNVE.2M2EWJDQ4AQFV@rcpassos.me> (raw)
In-Reply-To: <f1accf74-c527-4c53-9321-84dbcd8fd729@app.fastmail.com>

Hi David,

It took me a while to get back to this one, because there was a bunch I
had to dig, and I had little time available these weeks.

On Fri Jul 31, 2026 at 8:17 AM -03, David Rheinsberg wrote:
> `hdev->driver_input_lock` serializes all probe/remove/event callbacks. Can you elaborate how this is triggered?
>
> I can see that external APIs like debugfs and other sysfs registrations can trigger this, but they are deinitialized before cancelling the work, aren't they?

Yes, you are right. This is a false alarm by sashiko.
wiidebug_deinit and device_remove_file are called before
cancel_work_sync(->queue.worker).
This is even more clear after my refactor of the wiimote_destroy
function (that I will send in the v4).

Before arriving at this conclusion, I tried adding delays to help
trigger the uaf with xwiimote, and failed :)

Thanks, I will drop this patch from the series.
Rafael Passos

      reply	other threads:[~2026-08-17 20:20 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-29 16:49 [PATCH v3 0/4] HID: wiimote: new LED behavior on connect, scoped guards, uaf Rafael Passos
2026-07-29 16:49 ` [PATCH v3 1/4] HID: wiimote: turn on the LEDs indicating the controller id Rafael Passos
2026-07-29 17:07   ` sashiko-bot
2026-07-31  9:02   ` David Rheinsberg
2026-08-02  0:21     ` Rafael Passos
2026-08-06  8:01       ` David Rheinsberg
2026-07-29 16:49 ` [PATCH v3 2/4] HID: wiimote: replace spinlock pairs with scoped_guard Rafael Passos
2026-07-29 17:07   ` sashiko-bot
2026-07-31  9:08   ` David Rheinsberg
2026-07-29 16:49 ` [PATCH v3 3/4] HID: wiimote: use scoped cleanup in wiimote and led probes Rafael Passos
2026-07-29 17:14   ` sashiko-bot
2026-07-31 11:18   ` David Rheinsberg
2026-08-02  0:24     ` Rafael Passos
2026-07-29 16:49 ` [PATCH v3 4/4] HID: wiimote: fix uaf when hid events are handled during destroy Rafael Passos
2026-07-29 17:14   ` sashiko-bot
2026-07-31 11:17   ` David Rheinsberg
2026-08-17 20:20     ` Rafael Passos [this message]

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