Re: [PATCH] watchdog: ixp4xx: fix reference leak on platform_device_register() failure

[Linus Walleij]

Hi Guangshuo,

thanks for your patch!

On Mon, Apr 13, 2026 at 5:47 PM Guangshuo Li <lgs201920130244@xxxxxxxxx> wrote:

> ixp4xx_timer_probe() directly returns the result of
> platform_device_register(&ixp4xx_watchdog_device). When registration
> fails, the embedded struct device in ixp4xx_watchdog_device has already
> been initialized by device_initialize(), but the failure path does not
> drop the device reference, leading to a reference leak.
(...)

> -       return platform_device_register(&ixp4xx_watchdog_device);
> +       ret = platform_device_register(&ixp4xx_watchdog_device);
> +       if (ret)
> +               platform_device_put(&ixp4xx_watchdog_device);

If the problem in the description is indeed there, it seems the bug
is inside platform_device_register(), surely a function returning an
error code is supposed to clean up any resources it takes before
returning an error. It seems wrong to try to fix this in all the
consumers.

Yours,
Linus Walleij