linux-kernel - Re: [PATCH 04/23] gpiolib: Fix resource leaks on errors in lineinfo_changed

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Message-ID: <CAMRc=Mc4UoXif=vwUQG1jYW8G3QziZwbdcfvZGquytdrd4SBpg@mail.gmail.com>
Date: Fri, 16 Jan 2026 13:26:01 +0000
From: Bartosz Golaszewski <brgl@...nel.org>
To: Tzung-Bi Shih <tzungbi@...nel.org>
Cc: 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, Benson Leung <bleung@...omium.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, "Rafael J . Wysocki" <rafael@...nel.org>, 
	Danilo Krummrich <dakr@...nel.org>, Bartosz Golaszewski <brgl@...ev.pl>, Linus Walleij <linusw@...nel.org>
Subject: Re: [PATCH 04/23] gpiolib: Fix resource leaks on errors in lineinfo_changed_notify()

On Fri, 16 Jan 2026 09:10:17 +0100, Tzung-Bi Shih <tzungbi@...nel.org> said:
> On error handling paths, lineinfo_changed_notify() doesn't free the
> allocated resources which results leaks.  Fix it.
>
> Cc: stable@...r.kernel.org
> Fixes: d4cd0902c156 ("gpio: cdev: make sure the cdev fd is still active before emitting events")
> Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
> ---
>  drivers/gpio/gpiolib-cdev.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index ba1eae15852d..6196aab5ed74 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -2549,7 +2549,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
>  	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
>  	if (!ctx) {
>  		pr_err("Failed to allocate memory for line info notification\n");
> -		return NOTIFY_DONE;
> +		goto err_put_fp;
>  	}
>
>  	ctx->chg.event_type = action;
> @@ -2563,6 +2563,9 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
>  	queue_work(ctx->gdev->line_state_wq, &ctx->work);
>
>  	return NOTIFY_OK;
> +err_put_fp:
> +	fput(fp);
> +	return NOTIFY_DONE;
>  }
>
>  static int gpio_device_unregistered_notify(struct notifier_block *nb,
> --
> 2.52.0.457.g6b5491de43-goog
>
>

There's only one place where you need this fput(), please do it directly in
the error path of kzalloc() and drop the label.

Bart