linux-kernel - Re: [PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev

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Message-ID: <CAMRc=Mdngn4c4QW_ZhDs+VcDovO0nQ9XO2PkrNdrbyHDxrm3AA@mail.gmail.com>
Date: Tue, 20 Jan 2026 09:50:42 +0100
From: Bartosz Golaszewski <brgl@...nel.org>
To: Tzung-Bi Shih <tzungbi@...nel.org>
Cc: Benson Leung <bleung@...omium.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	"Rafael J . Wysocki" <rafael@...nel.org>, Danilo Krummrich <dakr@...nel.org>, Linus Walleij <linusw@...nel.org>, 
	Jonathan Corbet <corbet@....net>, Shuah Khan <shuah@...nel.org>, linux-doc@...r.kernel.org, 
	linux-kernel@...r.kernel.org, chrome-platform@...ts.linux.dev, 
	linux-kselftest@...r.kernel.org, 
	Laurent Pinchart <laurent.pinchart@...asonboard.com>, 
	Wolfram Sang <wsa+renesas@...g-engineering.com>, Simona Vetter <simona.vetter@...ll.ch>, 
	Dan Williams <dan.j.williams@...el.com>, Jason Gunthorpe <jgg@...dia.com>, linux-gpio@...r.kernel.org, 
	stable@...r.kernel.org
Subject: Re: [PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()

On Fri, Jan 16, 2026 at 9:11 AM Tzung-Bi Shih <tzungbi@...nel.org> wrote:
>
> On error handling paths, gpiolib_cdev_register() doesn't free the
> allocated resources which results leaks.  Fix it.
>
> Cc: stable@...r.kernel.org
> Fixes: 7b9b77a8bba9 ("gpiolib: add a per-gpio_device line state notification workqueue")
> Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
> Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
> ---
>  drivers/gpio/gpiolib-cdev.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index 3735c9fe1502..ba1eae15852d 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -2797,16 +2797,23 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
>
>         ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
>         if (ret)
> -               return ret;
> +               goto err_free_workqueue;
>

I need to drop this because it jumps over the guard(). I think you'll
have to free the workqueue locally here instead.

Can you send a separate v2?

Bart

>         guard(srcu)(&gdev->srcu);
>         gc = srcu_dereference(gdev->chip, &gdev->srcu);
> -       if (!gc)
> -               return -ENODEV;
> +       if (!gc) {
> +               ret = -ENODEV;
> +               goto err_free_cdev;
> +       }
>
>         gpiochip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id);
>
>         return 0;
> +err_free_cdev:
> +       cdev_device_del(&gdev->chrdev, &gdev->dev);
> +err_free_workqueue:
> +       destroy_workqueue(gdev->line_state_wq);
> +       return ret;
>  }
>
>  void gpiolib_cdev_unregister(struct gpio_device *gdev)
> --
> 2.52.0.457.g6b5491de43-goog
>