Re: [PATCH v2] usb: misc: uss720: properly clean up reference in uss720_probe()

[Oliver Neukum <oneukum@suse.com>]

Hi,

On 23.02.26 12:17, Greg Kroah-Hartman wrote:
> If get_1284_register() fails, the usb device reference count is
> incorrect and needs to be properly dropped before returning.
> 
> Cc: stable <stable@kernel.org>
> Assisted-by: gkh_clanker_2000
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>   v2: properly clean up the previously allocated resources by jumping to
>       the error path and not just retrning directly
> 
>   drivers/usb/misc/uss720.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
> index ec8bd968c4de..54107bf280df 100644
> --- a/drivers/usb/misc/uss720.c
> +++ b/drivers/usb/misc/uss720.c
> @@ -735,8 +735,10 @@ static int uss720_probe(struct usb_interface *intf,
>   	 * here. */
>   	ret = get_1284_register(pp, 0, &reg, GFP_KERNEL);
>   	dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
> -	if (ret < 0)
> -		return ret;
> +	if (ret < 0) {
> +		usb_put_dev(usbdev);
> +		goto probe_abort;

This jumps to probe_abort, which calls destroy_priv() indirectly
via kref_put(). Either that works, which would mean that you must
_not_ do a second usb_put_dev() or it does not, in which case the
earlier error handling for parport_register_port() is incorrect.

Either way, there is a problem.

	Regards
		Oliver