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Subject: Re: [PATCH] usb: usbip: fix a refcount leak in stub_probe()
To:     Hangyu Hua <hbh25y@gmail.com>, valentina.manea.m@gmail.com,
        shuah@kernel.org, gregkh@linuxfoundation.org, khoroshilov@ispras.ru
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Shuah Khan <skhan@linuxfoundation.org>
References: <20220406061713.18938-1-hbh25y@gmail.com>
From:   Shuah Khan <skhan@linuxfoundation.org>
Message-ID: <4341150b-195c-a896-1f6a-8715bbb539e2@linuxfoundation.org>
Date:   Wed, 6 Apr 2022 12:13:57 -0600
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On 4/6/22 12:17 AM, Hangyu Hua wrote:
> usb_get_dev is called in stub_device_alloc. When stub_probe fails after
> that, usb_put_dev needs to be used.
> 

Thank you for the patch. Please include details on how you found
this problem.

Nit: Change this to:

usb_get_dev() is called in stub_device_alloc(). When stub_probe() fails
after that, usb_put_dev() needs to be called to release the reference.

> Fix this by moving usb_put_dev() to sdev_free
> 

Nit: Change this to:

Fix this by moving usb_put_dev() to sdev_free error path handling.

> Fixes: 3ff67445750a ("usbip: fix error handling in stub_probe()")
> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
>   drivers/usb/usbip/stub_dev.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
> index d8d3892e5a69..3c6d452e3bf4 100644
> --- a/drivers/usb/usbip/stub_dev.c
> +++ b/drivers/usb/usbip/stub_dev.c
> @@ -393,7 +393,6 @@ static int stub_probe(struct usb_device *udev)
>   
>   err_port:
>   	dev_set_drvdata(&udev->dev, NULL);
> -	usb_put_dev(udev);
>   
>   	/* we already have busid_priv, just lock busid_lock */
>   	spin_lock(&busid_priv->busid_lock);
> @@ -408,6 +407,7 @@ static int stub_probe(struct usb_device *udev)
>   	put_busid_priv(busid_priv);
>   
>   sdev_free:
> +	usb_put_dev(udev);
>   	stub_device_free(sdev);
>   
>   	return rc;
> 

With the above addressed:

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah