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SubjectRe: [PATCH] Input: Fix a ref counting issue
Hi Christophe,

On Sun, Nov 29, 2020 at 09:45:16AM +0100, Christophe JAILLET wrote:
> In case of a managed resource, 'devm_input_device_release()' already has a
> 'input_put_device(dev)' call.
>
> Avoid a double reference decrement by explicitly calling
> 'input_put_device()' only on non-managed input device.

This patch is incorrect, as devres_destroy() that is used in
input_free_device(), unlike devres_releasde(), does not actually call
the "release" function. It simply destroys the devres object, but does
not clear associated resources.

>
> Fixes: 2be975c6d920 ("Input: introduce managed input devices (add devres support)")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> This patch is completely speculative and compile tested only.
> ---
> drivers/input/input.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index 3cfd2c18eebd..c09c9f020667 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -1920,7 +1920,8 @@ void input_free_device(struct input_dev *dev)
> devm_input_device_release,
> devm_input_device_match,
> dev));
> - input_put_device(dev);
> + else
> + input_put_device(dev);
> }
> }
> EXPORT_SYMBOL(input_free_device);
> --
> 2.27.0
>

Thanks.

--
Dmitry

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