Re: [PATCH] Input: maplemouse - fix NULL pointer dereference in open()

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Florian,

On Mon, Jun 29, 2026 at 01:07:15AM +0200, Florian Fuchs wrote:
> Commit 555c765b0cc2 ("Input: mouse - drop unnecessary calls to
> input_set_drvdata") dropped the input_set_drvdata() call in probe
> because the data appeared to be unused. However, dc_mouse_open() and
> dc_mouse_close() were using maple_get_drvdata(to_maple_dev(&dev->dev)).
> This actually retrieves driver data from the input device's embedded
> struct device. After input_set_drvdata() was removed, that lookup started
> returning NULL and opening the input device dereferences mse->mdev.
> 
> Restore input_set_drvdata() and convert open() and close() to use
> input_get_drvdata() so the dependency is no longer hidden.

Thank you for the patch. While the patch itself is correct I believe the
main culprit is actually 6b3480855aad ("maple: input: fix up maple mouse driver")
that introduced incorrect use of
maple_get_drvdata() and to_maple_dev() on instance of input_dev instead
of maple_device.

I added another Fixes: tag and applied.

Thanks.

-- 
Dmitry