Date:   Wed, 12 Jan 2022 16:30:39 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-ide@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH][RESEND] sata_fsl: Use struct_group() for memcpy() region
Message-ID: <202201121628.A8B11A1@keescook>
References: <20220112220652.3952944-1-keescook@chromium.org>
 <df3eefdc-d8d1-48fa-f5f7-9c2f2382842b@kernel.dk>
 <202201121515.8679164D6@keescook>
 <ec4d9eb0-3999-db52-1eec-bc6351dd4f07@opensource.wdc.com>
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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.

> 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

Thanks!

-- 
Kees Cook