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[PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()

Tzung-Bi Shih posted 23 patches 3 weeks, 2 days ago
[PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()
Posted by Tzung-Bi Shih 3 weeks, 2 days ago 
On error handling paths, gpiolib_cdev_register() doesn't free the
allocated resources which results leaks.  Fix it.

Cc: stable@vger.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@kernel.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;
 
 	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
Re: [PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()
Posted by Bartosz Golaszewski 2 weeks, 5 days ago 
On Fri, Jan 16, 2026 at 9:11 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On error handling paths, gpiolib_cdev_register() doesn't free the
> allocated resources which results leaks.  Fix it.
>
> Cc: stable@vger.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@kernel.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
>
Re: [PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()
Posted by Tzung-Bi Shih 2 weeks, 5 days ago 
On Tue, Jan 20, 2026 at 09:50:42AM +0100, Bartosz Golaszewski wrote:
> On Fri, Jan 16, 2026 at 9:11 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
> >
> > On error handling paths, gpiolib_cdev_register() doesn't free the
> > allocated resources which results leaks.  Fix it.
> >
> > Cc: stable@vger.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@kernel.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?

v2: https://lore.kernel.org/linux-gpio/20260120092650.2305319-1-tzungbi@kernel.org/

Heads up: I'll respin the whole series for targeting v7.0-rc1 for:
- Rebase after you applied some of the patches.
- I found you prefer "gpio" to "gpiolib" in the title prefix.
- I found yet another build warning when testing with
  https://lore.kernel.org/linux-gpio/202601200022.ZFwz8K6u-lkp@intel.com/
Re: [PATCH 02/23] gpiolib: cdev: Fix resource leaks on errors in gpiolib_cdev_register()
Posted by Bartosz Golaszewski 2 weeks, 5 days ago 
On Tue, Jan 20, 2026 at 10:34 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> On Tue, Jan 20, 2026 at 09:50:42AM +0100, Bartosz Golaszewski wrote:
> > On Fri, Jan 16, 2026 at 9:11 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
> > >
> > > On error handling paths, gpiolib_cdev_register() doesn't free the
> > > allocated resources which results leaks.  Fix it.
> > >
> > > Cc: stable@vger.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@kernel.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?
>
> v2: https://lore.kernel.org/linux-gpio/20260120092650.2305319-1-tzungbi@kernel.org/
>
> Heads up: I'll respin the whole series for targeting v7.0-rc1 for:
> - Rebase after you applied some of the patches.

I guess this concerns the device_initialize() rework? Yeah v7.0-rc1 is
good timing.

> - I found you prefer "gpio" to "gpiolib" in the title prefix.

Just makes the line shorter.

> - I found yet another build warning when testing with
>   https://lore.kernel.org/linux-gpio/202601200022.ZFwz8K6u-lkp@intel.com/

Yeah, this is the one I referred to in my previous email, just forgot
to link it.

Bart

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