Date:   Wed, 12 Jan 2022 15:15:22 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     linux-ide@vger.kernel.org,
        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH][RESEND] sata_fsl: Use struct_group() for memcpy() region
Message-ID: <202201121515.8679164D6@keescook>
References: <20220112220652.3952944-1-keescook@chromium.org>
 <df3eefdc-d8d1-48fa-f5f7-9c2f2382842b@kernel.dk>
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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. :)

-- 
Kees Cook