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

[gregkh@xxxxxxxxxxxxxxxxxxx]

On Thu, Jun 29, 2023 at 05:56:30AM +0000, Christophe Leroy wrote:
> 
> 
> 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.

This is fine as-is, no need to change anything.

greg k-h