[PATCH] ASoC: mediatek: common: Fix refcount leak in parse_dai_link_info

[Guenter Roeck]

On Mon, Apr 10, 2023 at 5:34 PM Aashish Sharma <shraash at google.com> wrote:
>
> Add missing of_node_put()s before the returns to balance
> of_node_get()s and of_node_put()s, which may get unbalanced
> in case the for loop 'for_each_available_child_of_node' returns
> early.
>
> Fixes: 4302187d955f ("ASoC: mediatek: common: add soundcard driver common code")
> Reported-by: kernel test robot <lkp at intel.com>
> Reported-by: Julia Lawall <julia.lawall at inria.fr>
> Link: https://lore.kernel.org/r/202304090504.2K8L6soj-lkp@intel.com/
> Signed-off-by: Aashish Sharma <shraash at google.com>

Reviewed-by: Guenter Roeck <groeck at chromium.org>

> ---
>  sound/soc/mediatek/common/mtk-soundcard-driver.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/sound/soc/mediatek/common/mtk-soundcard-driver.c b/sound/soc/mediatek/common/mtk-soundcard-driver.c
> index 7c55c2cb1f21..738093451ccb 100644
> --- a/sound/soc/mediatek/common/mtk-soundcard-driver.c
> +++ b/sound/soc/mediatek/common/mtk-soundcard-driver.c
> @@ -47,20 +47,26 @@ int parse_dai_link_info(struct snd_soc_card *card)
>         /* Loop over all the dai link sub nodes */
>         for_each_available_child_of_node(dev->of_node, sub_node) {
>                 if (of_property_read_string(sub_node, "link-name",
> -                                           &dai_link_name))
> +                                           &dai_link_name)) {
> +                       of_node_put(sub_node);
>                         return -EINVAL;
> +               }
>
>                 for_each_card_prelinks(card, i, dai_link) {
>                         if (!strcmp(dai_link_name, dai_link->name))
>                                 break;
>                 }
>
> -               if (i >= card->num_links)
> +               if (i >= card->num_links) {
> +                       of_node_put(sub_node);
>                         return -EINVAL;
> +               }
>
>                 ret = set_card_codec_info(card, sub_node, dai_link);
> -               if (ret < 0)
> +               if (ret < 0) {
> +                       of_node_put(sub_node);
>                         return ret;
> +               }
>         }
>
>         return 0;
> --
> 2.40.0.577.gac1e443424-goog
>