[PATCH] mmc: meson-gx: fix return value check of mmc_add_host()

[neil.armstrong at linaro.org]

On 08/11/2022 13:34, Yang Yingliang wrote:
> mmc_add_host() may return error, if we ignore its return value,
> it will lead two issues:
> 1. The memory that allocated in mmc_alloc_host() is leaked.
> 2. In the remove() path, mmc_remove_host() will be called to
>     delete device, but it's not added yet, it will lead a kernel
>     crash because of null-ptr-deref in device_del().
> 
> Fix this by checking the return value and goto error path which
> will call mmc_free_host().
> 
> Fixes: 51c5d8447bd7 ("MMC: meson: initial support for GX platforms")
> Signed-off-by: Yang Yingliang <yangyingliang at huawei.com>
> ---
>   drivers/mmc/host/meson-gx-mmc.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index df05e60bed9a..6e5ea0213b47 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -1335,7 +1335,9 @@ static int meson_mmc_probe(struct platform_device *pdev)
>   	}
>   
>   	mmc->ops = &meson_mmc_ops;
> -	mmc_add_host(mmc);
> +	ret = mmc_add_host(mmc);
> +	if (ret)
> +		goto err_free_irq;
>   
>   	return 0;
>   


Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>