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

[Guenter Roeck]

On 4/19/26 13:22, Linus Walleij wrote:
> Hi Guangshuo,
> 
> thanks for your patch!
> 
> On Mon, Apr 13, 2026 at 5:47 PM Guangshuo Li <lgs201920130244 at gmail.com> 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.
> 

 From platform_device_register():

/**
  * platform_device_register - add a platform-level device
  * @pdev: platform device we're adding
  *
  * NOTE: _Never_ directly free @pdev after calling this function, even if it
  * returned an error! Always use platform_device_put() to give up the
  * reference initialised in this function instead.
  */

Not that any code actually does that as far as I can see, but isn't
the above doing exactly what the comment suggests ?

Thanks,
Guenter