Re: [PATCH] crypto: marvell/cesa - Fix type mismatch warning

From: Kees Cook
Date: Wed May 31 2023 - 12:31:33 EST


On Wed, May 31, 2023 at 06:58:10PM +0800, Herbert Xu wrote:
> On Tue, May 30, 2023 at 03:48:49PM -0700, Kees Cook wrote:
> > On Tue, 23 May 2023 10:33:04 +0200, Arnd Bergmann wrote:
> > > From: Arnd Bergmann <arnd@xxxxxxxx>
> > >
> > > Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") uncovered
> > > a type mismatch in cesa 3des support that leads to a memcpy beyond the
> > > end of a structure:
> > >
> > > In function 'fortify_memcpy_chk',
> > > inlined from 'mv_cesa_des3_ede_setkey' at drivers/crypto/marvell/cesa/cipher.c:307:2:
> > > include/linux/fortify-string.h:583:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
> > > 583 | __write_overflow_field(p_size_field, size);
> > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > >
> > > [...]
> >
> > Applied to for-next/hardening, thanks!
> >
> > [1/1] crypto: marvell/cesa - Fix type mismatch warning
> > https://git.kernel.org/kees/c/37f3abddda8d
>
> Why did you apply it to your tree? This patch makes sense on its
> own regardless of the fortify changes.

I snagged it since a week had gone by with no additional discussion and
it fixed an issue exposed by work in the hardening tree. Let me know if
you'd prefer I drop it for you to carry instead.

-Kees

--
Kees Cook