On Tue, Jan 27, 2015 at 12:30:19PM +0100, Krzysztof Kozlowski wrote:
> The return value of power_supply_register() call was not checked and
> even on error probe() function returned 0. If registering failed then
> during unbind the driver tried to unregister power supply which was not
> actually registered.
>
> This could lead to memory corruption because power_supply_unregister()
> unconditionally cleans up given power supply.
>
> Fix this by checking return status of power_supply_register() call. In
> case of failure, unregister the hwmon device and fail the probe. Add a
> fixme note about missing hwmon_device_unregister() in driver removal.
>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> Fixes: 9be0fcb5ed46 ("compal-laptop: add JHL90, battery & hwmon interface")
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> drivers/platform/x86/compal-laptop.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/compal-laptop.c b/drivers/platform/x86/compal-laptop.c
> index 15c0fab2bfa1..cf55a9246f12 100644
> --- a/drivers/platform/x86/compal-laptop.c
> +++ b/drivers/platform/x86/compal-laptop.c
> @@ -1036,12 +1036,16 @@ static int compal_probe(struct platform_device *pdev)
>
> /* Power supply */
> initialize_power_supply_data(data);
> - power_supply_register(&compal_device->dev, &data->psy);
> + err = power_supply_register(&compal_device->dev, &data->psy);
> + if (err < 0)
> + goto psy_err;
>
> platform_set_drvdata(pdev, data);
>
> return 0;
>
> +psy_err:
> + hwmon_device_unregister(hwmon_dev);
> remove:
> sysfs_remove_group(&pdev->dev.kobj, &compal_platform_attr_group);
> return err;
> @@ -1072,6 +1076,7 @@ static int compal_remove(struct platform_device *pdev)
>
> data = platform_get_drvdata(pdev);
> power_supply_unregister(&data->psy);
> + /* FIXME: missing hwmon_device_unregister() */
Is this FIXME a leftover? Is there a reason we can't fix this now instead of
adding a FIXME?
--
Darren Hart
Intel Open Source Technology Center
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