diff mbox series

mmc: wbsd: fix return value check of mmc_add_host()

Message ID 20221109133237.3273558-1-yangyingliang@huawei.com
State New
Headers show
Series mmc: wbsd: fix return value check of mmc_add_host() | expand

Commit Message

Yang Yingliang Nov. 9, 2022, 1:32 p.m. UTC
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().


So fix this by checking the return value and goto error path which
will call mmc_free_host(), besides, other resources also need be
released.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/mmc/host/wbsd.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Ulf Hansson Nov. 16, 2022, 4:17 p.m. UTC | #1
On Wed, 9 Nov 2022 at 14:34, Yang Yingliang <yangyingliang@huawei.com> 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().
>
>
> So fix this by checking the return value and goto error path which
> will call mmc_free_host(), besides, other resources also need be
> released.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/wbsd.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
> index 67ecd342fe5f..7c7ec8d10232 100644
> --- a/drivers/mmc/host/wbsd.c
> +++ b/drivers/mmc/host/wbsd.c
> @@ -1698,7 +1698,17 @@ static int wbsd_init(struct device *dev, int base, int irq, int dma,
>          */
>         wbsd_init_device(host);
>
> -       mmc_add_host(mmc);
> +       ret = mmc_add_host(mmc);
> +       if (ret) {
> +               if (!pnp)
> +                       wbsd_chip_poweroff(host);
> +
> +               wbsd_release_resources(host);
> +               wbsd_free_mmc(dev);
> +
> +               mmc_free_host(mmc);
> +               return ret;
> +       }
>
>         pr_info("%s: W83L51xD", mmc_hostname(mmc));
>         if (host->chip_id != 0)
> --
> 2.25.1
>
diff mbox series

Patch

diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index 67ecd342fe5f..7c7ec8d10232 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1698,7 +1698,17 @@  static int wbsd_init(struct device *dev, int base, int irq, int dma,
 	 */
 	wbsd_init_device(host);
 
-	mmc_add_host(mmc);
+	ret = mmc_add_host(mmc);
+	if (ret) {
+		if (!pnp)
+			wbsd_chip_poweroff(host);
+
+		wbsd_release_resources(host);
+		wbsd_free_mmc(dev);
+
+		mmc_free_host(mmc);
+		return ret;
+	}
 
 	pr_info("%s: W83L51xD", mmc_hostname(mmc));
 	if (host->chip_id != 0)