Re: [PATCH] platform/loongarch: laptop: fix possible UAF in generic_acpi_laptop_init()

[Huacai Chen]

Hi, Yingliang,

Thank you for your patches, but could you please merge the two trivial
patches to a single one?

Huacai

On Thu, Oct 13, 2022 at 9:12 PM Yang Yingliang <yangyingliang@xxxxxxxxxx> wrote:
>
> Current the return value of 'sub_driver->init' is not checked,
> if sparse_keymap_setup() called in the init function fails,
> 'generic_inputdev' is freed, then it willl lead a UAF when
> using it in generic_acpi_laptop_init(). Fix it by checking
> return value. Set generic_inputdev to NULL after free to avoid
> double free it.
>
> Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver")
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
>  drivers/platform/loongarch/loongson-laptop.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c
> index f0166ad5d2c2..a665fd1042ac 100644
> --- a/drivers/platform/loongarch/loongson-laptop.c
> +++ b/drivers/platform/loongarch/loongson-laptop.c
> @@ -448,6 +448,7 @@ static int __init event_init(struct generic_sub_driver *sub_driver)
>         if (ret < 0) {
>                 pr_err("Failed to setup input device keymap\n");
>                 input_free_device(generic_inputdev);
> +               generic_inputdev = NULL;
>
>                 return ret;
>         }
> @@ -502,8 +503,11 @@ static int __init generic_subdriver_init(struct generic_sub_driver *sub_driver)
>         if (ret)
>                 return -EINVAL;
>
> -       if (sub_driver->init)
> -               sub_driver->init(sub_driver);
> +       if (sub_driver->init) {
> +               ret = sub_driver->init(sub_driver);
> +               if (ret)
> +                       goto err_out;
> +       }
>
>         if (sub_driver->notify) {
>                 ret = setup_acpi_notify(sub_driver);
> --
> 2.25.1
>