Re: [PATCH v2 1/3] mmc: sdio: fix of node refcount leak in sdio_add_func()

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 2 Nov 2022 at 02:27, Yang Yingliang <yangyingliang@huawei.com> wrote:
>
> If device_add() returns error in sdio_add_func(), sdio function is not
> presented, so the node refcount that hold in sdio_set_of_node() can not
> be put in sdio_remove_func() which is called from error path. Fix this
> by calling of_node_put() if device_add() fails.
>
> Fixes: 25185f3f31c9 ("mmc: Add SDIO function devicetree subnode parsing")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/mmc/core/sdio_bus.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
> index babf21a0adeb..b9308813a226 100644
> --- a/drivers/mmc/core/sdio_bus.c
> +++ b/drivers/mmc/core/sdio_bus.c
> @@ -365,6 +365,8 @@ int sdio_add_func(struct sdio_func *func)
>         ret = device_add(&func->dev);
>         if (ret == 0)
>                 sdio_func_set_present(func);
> +       else
> +               of_node_put(func->dev.of_node);

I think it would be better to change the sdio_remove_func() to manage
this. In principle sdio_func_present() should not make
sdio_remove_func() to return immediately, but rather just control
whether device_del() needs to be called or not.

>
>         return ret;
>  }


Kind regards
Uffe