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Date:   Fri, 19 Aug 2022 10:36:22 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Andrey Strachuk <strochuk@ispras.ru>
Cc:     Peter Chen <peter.chen@kernel.org>,
        Pawel Laszczak <pawell@cadence.com>,
        Roger Quadros <rogerq@kernel.org>,
        Aswath Govindraju <a-govindraju@ti.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        ldv-project@linuxtesting.org
Subject: Re: [PATCH v2] usb: cdns3: change place of NULL check in
 cdns3_gadget_ep_enable()
Message-ID: <Yv9LhgZgDCdA0hG8@kroah.com>
References: <16589929667170@kroah.com>
 <20220728163014.247082-1-strochuk@ispras.ru>
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On Thu, Jul 28, 2022 at 07:30:14PM +0300, Andrey Strachuk wrote:
> If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid and
> priv_ep->cdns3_dev causes panic.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Andrey Strachuk <strochuk@ispras.ru>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> ---
>  drivers/usb/cdns3/cdns3-gadget.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

No information on what changed from v1 to v2 :(

> 
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 5c15c48952a6..51de7457a3b8 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -2284,11 +2284,14 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
>  	int ret = 0;
>  	int val;
>  
> +	if (!ep)
> +		return -EINVAL;

How can ep ever be NULL at all?  Why does this need to be checked?

thanks,

greg k-h