Re: [PATCH][RESEND] sata_fsl: Use struct_group() for memcpy() region

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 1/13/22 09:30, Kees Cook wrote:
> On Thu, Jan 13, 2022 at 08:47:37AM +0900, Damien Le Moal wrote:
>> On 1/13/22 08:15, Kees Cook wrote:
>>> On Wed, Jan 12, 2022 at 03:23:40PM -0700, Jens Axboe wrote:
>>>> On 1/12/22 3:06 PM, Kees Cook wrote:
>>>>> In preparation for FORTIFY_SOURCE performing compile-time and run-time
>>>>> field bounds checking for memcpy(), memmove(), and memset(), avoid
>>>>> intentionally writing across neighboring fields.
>>>>>
>>>>> Use struct_group() in struct command_desc around members acmd and fill,
>>>>> so they can be referenced together. This will allow memset(), memcpy(),
>>>>> and sizeof() to more easily reason about sizes, improve readability,
>>>>> and avoid future warnings about writing beyond the end of acmd:
>>>>>
>>>>> In function 'fortify_memset_chk',
>>>>>     inlined from 'sata_fsl_qc_prep' at drivers/ata/sata_fsl.c:534:3:
>>>>> ./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
>>>>>   199 |    __write_overflow_field();
>>>>>       |    ^~~~~~~~~~~~~~~~~~~~~~~~
>>>>>
>>>>> Cc: Jens Axboe <axboe@kernel.dk>
>>>>> Cc: linux-ide@vger.kernel.org
>>>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>>>> ---
>>>>> Jens, can you take (or Ack) this? It's a dependency for the FORTIFY_SOURCE
>>>>> improvements that are close to being finished. :)
>>>>
>>>> I don't maintain libata anymore, so Damien is the guy to nudge ;-)
>>>
>>> Ah-ha, okay, thanks.
>>>
>>> /me waves "hi" to Damien. :)
>>
>> Hi Kees,
>>
>> This is already queued up in libata tree for-5.17 branch. I have not
>> sent my PR to Linus yet as I am letting things soack a little longer in
>> for-next (for the various arch compile tests).
> 
> Oh thank you! Sorry I missed the pull. I didn't see it in -next yet, so
> I assumed it hadn't been pulled anywhere.

Uh... Weird. That one has been in libata for-next since a while back. So
it should be in linux-next.

> 
>> Please check that branch to see if all is OK !
> 
> Found it:
> https://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata.git/log/?h=for-next
> 
> Yup, looks good:
> https://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata.git/commit/?h=for-next&id=23c72ffedeed6d513144fa09834b1eb0cb2b7373

OK !

> 
> Thanks!
> 


-- 
Damien Le Moal
Western Digital Research