Re: [PATCH] usb-serial: fix port device refcount leak when device_add() fails

[Johan Hovold <johan@kernel.org>]

On Mon, Apr 13, 2026 at 12:53:11AM +0800, Guangshuo Li wrote:
> usb_serial_probe() initializes each port device with
> device_initialize() before registering it with device_add().
> 
> If device_add() fails, the current code only logs an error and
> continues, but does not drop the reference acquired by
> device_initialize(). This leaves the failed port device referenced
> until a later teardown path, if any.
> 
> Fix it by calling put_device() when device_add() fails. Also clear
> serial->port[i] after put_device() so destroy_serial() will not try
> to put the same device again.

Any port that fails to register is released in destroy_serial() which is
called when the last reference to the device is dropped (e.g. when the
device is disconnected).

So there is nothing to fix here.

Are you using some kind of tool to find these "issues"?

Johan