Re: [PATCH] usb: gadget: fsl_qe_udc: validate endpoint index for ch9 udc

[Christophe Leroy]

Le 28/06/2023 à 23:10, Leo Li a écrit :
> 
> 
>> -----Original Message-----
>> From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
>> Sent: Wednesday, June 28, 2023 2:40 PM
>> To: Leo Li <leoyang.li@xxxxxxx>; Ma Ke <make_ruc2021@xxxxxxx>
>> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linuxppc-
>> dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
>> Subject: Re: [PATCH] usb: gadget: fsl_qe_udc: validate endpoint index for
>> ch9 udc
>>
>>
>>
>> Le 28/06/2023 à 19:04, Leo Li a écrit :
>>>
>>>
>>>> -----Original Message-----
>>>> From: Ma Ke <make_ruc2021@xxxxxxx>
>>>> Sent: Wednesday, June 28, 2023 3:15 AM
>>>> To: Leo Li <leoyang.li@xxxxxxx>
>>>> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linuxppc-
>>>> dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ma Ke
>>>> <make_ruc2021@xxxxxxx>
>>>> Subject: [PATCH] usb: gadget: fsl_qe_udc: validate endpoint index for
>>>> ch9 udc
>>>>
>>>> We should verify the bound of the array to assure that host may not
>>>> manipulate the index to point past endpoint array.
>>>>
>>>> Signed-off-by: Ma Ke <make_ruc2021@xxxxxxx>
>>>> ---
>>>>    drivers/usb/gadget/udc/fsl_qe_udc.c | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/usb/gadget/udc/fsl_qe_udc.c
>>>> b/drivers/usb/gadget/udc/fsl_qe_udc.c
>>>> index 3b1cc8fa30c8..f4e5cbd193b7 100644
>>>> --- a/drivers/usb/gadget/udc/fsl_qe_udc.c
>>>> +++ b/drivers/usb/gadget/udc/fsl_qe_udc.c
>>>> @@ -1959,6 +1959,8 @@ static void ch9getstatus(struct qe_udc *udc, u8
>>>> request_type, u16 value,
>>>>    	} else if ((request_type & USB_RECIP_MASK) ==
>>>> USB_RECIP_ENDPOINT) {
>>>>    		/* Get endpoint status */
>>>>    		int pipe = index & USB_ENDPOINT_NUMBER_MASK;
>>>> +		if (pipe >= USB_MAX_ENDPOINTS)
>>>> +			goto stall;
>>>
>>> Thanks.  This seems to be the right thing to do.  But normally we don't mix
>> declarations with code within a code block.  Could we re-arrange the code a
>> little bit so declarations stay on top?
>>
>> But we are at the start of a code block aren't we ?
> 
> But they were at the beginning of a { } block which is compliant with the C89 standard.  I know gcc is more relaxed from this.  But it is probably still good to stick to the standard?

Sorry I misread the patch and failed to see that the declaration block 
was continuing after the change.

So yes don't interleave code with declarations. Leave declaration at the 
top of a block with a blank line between declarations and code.

> 
>>
>> The only missing thing is the blank line between the declarations and the
>> code, so that we clearly see where declarations end and where code start.
>>
>>>
>>>>    		struct qe_ep *target_ep = &udc->eps[pipe];
>>>>    		u16 usep;
>>>>
>>>> --
>>>> 2.37.2
>>>