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Date:   Wed, 26 Jan 2022 14:53:31 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Saeed Mahameed <saeedm@nvidia.com>
Cc:     Leon Romanovsky <leon@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH RESEND] net/mlx5e: Use struct_group() for memcpy() region
Message-ID: <202201261452.97A809BE9C@keescook>
References: <20220124172242.2410996-1-keescook@chromium.org>
 <20220126212854.6gxffia7vj6cbtbh@sx1>
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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 <saeedm@nvidia.com>
> > Cc: Leon Romanovsky <leon@kernel.org>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: netdev@vger.kernel.org
> > Cc: linux-rdma@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> > 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