Subject: Re: [PATCH] usb: chipidea: udc: fix NULL pointer dereference if
 udc_start failed
To: Peter Chen <peter.chen@nxp.com>, Jisheng Zhang <jszhang@marvell.com>
References: <20170424123551.2465-1-jszhang@marvell.com>
 <20170425082948.GB873@b29397-desktop> <20170425171134.6a983841@xhacker>
 <HE1PR04MB1450634CE9C1D7FACC37DB4A8B1E0@HE1PR04MB1450.eurprd04.prod.outlook.com>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>
From: Stefan Wahren <stefan.wahren@i2se.com>
Message-ID: <0ac4bc53-dd26-0b90-c84e-a94d01a6d5e4@i2se.com>
Date: Tue, 25 Apr 2017 17:21:59 +0200
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Am 25.04.2017 um 11:20 schrieb Peter Chen:
>  
>>>> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
>>>> index f88e9157fad0..60a786c87c06 100644
>>>> --- a/drivers/usb/chipidea/udc.c
>>>> +++ b/drivers/usb/chipidea/udc.c
>>>> @@ -1984,6 +1984,7 @@ static void udc_id_switch_for_host(struct
>>>> ci_hdrc *ci)  int ci_hdrc_gadget_init(struct ci_hdrc *ci)  {
>>>>  	struct ci_role_driver *rdrv;
>>>> +	int ret;
>>>>
>>>>  	if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC))
>>>>  		return -ENXIO;
>>>> @@ -1996,7 +1997,10 @@ int ci_hdrc_gadget_init(struct ci_hdrc *ci)
>>>>  	rdrv->stop	= udc_id_switch_for_host;
>>>>  	rdrv->irq	= udc_irq;
>>>>  	rdrv->name	= "gadget";
>>>> -	ci->roles[CI_ROLE_GADGET] = rdrv;
>>>>
>>>> -	return udc_start(ci);
>>>> +	ret = udc_start(ci);
>>>> +	if (!ret)
>>>> +		ci->roles[CI_ROLE_GADGET] = rdrv;
>>>> +
>>>> +	return ret;
>>>>  }
>>>> --
>>> Thanks for fixing it. In fact, we'd better return failure if ret &&
>>> ret != -ENXIO at probe, it stands for initialization for host or
>>> gadget has failed.
>>>
>> I got your meaning. I'll cook v2. I don't have preference, since either one can fix the
>> issue.
>>
> Both are needed, you don't need to send this one again. Only a new one, thanks.

I'm not sure how easy it is to reproduce the issue.

Shouldn't make a Fixes tag sense at least?

>
> Peter
>
> _______________________________________________
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> linux-arm-kernel@lists.infradead.org
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