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@163.com>
---
 drivers/usb/gadget/udc/fsl_qe_udc.c | 2 ++
 1 file changed, 2 insertions(+)

> -----Original Message-----
> From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
> Sent: Thursday, June 29, 2023 3:41 AM
> To: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: Leo Li <leoyang.li@nxp.com>; Ma Ke <make_ruc2021@163.com>; linux-
> usb@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH] usb: gadget: fsl_qe_udc: validate endpoint index for
> ch9 udc
> 
> 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@csgroup.eu>
> > >> Sent: Wednesday, June 28, 2023 2:40 PM
> > >> To: Leo Li <leoyang.li@nxp.com>; Ma Ke <make_ruc2021@163.com>
> > >> Cc: gregkh@linuxfoundation.org; linux-usb@vger.kernel.org;
> > >> linuxppc- dev@lists.ozlabs.org; linux-kernel@vger.kernel.org
> > >> 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@163.com>
> > >>>> Sent: Wednesday, June 28, 2023 3:15 AM
> > >>>> To: Leo Li <leoyang.li@nxp.com>
> > >>>> Cc: gregkh@linuxfoundation.org; linux-usb@vger.kernel.org;
> > >>>> linuxppc- dev@lists.ozlabs.org; linux-kernel@vger.kernel.org; Ma
> > >>>> Ke <make_ruc2021@163.com>
> > >>>> 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@163.com>
> > >>>> ---
> > >>>>    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.

With the approval from Greg, I have no objection to the patch.

Acked-by: Li Yang <leoyang.li@nxp.com>

Regards,
Leo