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

[Christophe Leroy]

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 ?

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
>