Subject: Re: [PATCH RESEND] net/mlx5e: Use struct_group() for memcpy() region

From: Kees Cook <[email-masked]>
Date: Wed, 26 Jan 2022 14:53:31 -0800

On Wed, Jan 26, 2022 at 01:28:54PM -0800, Saeed Mahameed wrote:
> On 24 Jan 09:22, 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 vlan_ethhdr around members h_dest and
> > h_source, 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 h_dest.
> > 
> > "pahole" shows no size nor member offset changes to struct vlan_ethhdr.
> > "objdump -d" shows no object code changes.
> > 
> > Cc: Saeed Mahameed <[email-masked]>
> > Cc: Leon Romanovsky <[email-masked]>
> > Cc: "David S. Miller" <[email-masked]>
> > Cc: Jakub Kicinski <[email-masked]>
> > Cc: [email-masked]
> > Cc: [email-masked]
> > Signed-off-by: Kees Cook <[email-masked]>
> > ---
> > Since this results in no binary differences, I will carry this in my tree
> > unless someone else wants to pick it up. It's one of the last remaining
> > clean-ups needed for the next step in memcpy() hardening.
> > ---
> 
> applied to net-next-mlx5

Thanks! How often does net-next-mlx5 flush into net-next?

-- 
Kees Cook