Re: [PATCH v2 22/63] HID: cp2112: Use struct_group() for memcpy() region

From: Kees Cook
Date: Fri Aug 20 2021 - 11:49:19 EST


On Fri, Aug 20, 2021 at 03:01:43PM +0200, Jiri Kosina wrote:
> On Tue, 17 Aug 2021, 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 cp2112_string_report around members report,
> > length, type, and string, so they can be referenced together. This will
> > allow memcpy() and sizeof() to more easily reason about sizes, improve
> > readability, and avoid future warnings about writing beyond the end of
> > report.
> >
> > "pahole" shows no size nor member offset changes to struct
> > cp2112_string_report. "objdump -d" shows no meaningful object
> > code changes (i.e. only source line number induced differences.)
> >
> > Cc: Jiri Kosina <jikos@xxxxxxxxxx>
> > Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> > Cc: linux-input@xxxxxxxxxxxxxxx
> > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> Applied, thanks.

I'm not sure if my other HTML email got through, but please don't apply
these to separate trees -- struct_group() is introduced as part of this
series.

--
Kees Cook