Re: [PATCH -next] power: supply: generic-adc-battery: fix possible use-after-free in gab_remove()

From: Sebastian Reichel
Date: Thu Apr 08 2021 - 08:38:55 EST


Hi,

On Wed, Apr 07, 2021 at 05:17:06PM +0800, Yang Yingliang wrote:
> This driver's remove path calls cancel_delayed_work(). However, that
> function does not wait until the work function finishes. This means
> that the callback function may still be running after the driver's
> remove function has finished, which would result in a use-after-free.
>
> Fix by calling cancel_delayed_work_sync(), which ensures that
> the work is properly cancelled, no longer running, and unable
> to re-schedule itself.
>
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---

Thanks, queued.

-- Sebastian

> drivers/power/supply/generic-adc-battery.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/power/supply/generic-adc-battery.c b/drivers/power/supply/generic-adc-battery.c
> index 0032069fbc2b..66039c665dd1 100644
> --- a/drivers/power/supply/generic-adc-battery.c
> +++ b/drivers/power/supply/generic-adc-battery.c
> @@ -373,7 +373,7 @@ static int gab_remove(struct platform_device *pdev)
> }
>
> kfree(adc_bat->psy_desc.properties);
> - cancel_delayed_work(&adc_bat->bat_work);
> + cancel_delayed_work_sync(&adc_bat->bat_work);
> return 0;
> }
>
> --
> 2.25.1
>

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