netdev - Re: [Patch net] mlx5: fixup checksum for ethernet padding

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAM_iQpULYbELBO+81WWM7_HR=tqLzd9V161q5p0y68MCp0vqYg@mail.gmail.com>
Date:   Tue, 27 Nov 2018 17:38:32 -0800
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Saeed Mahameed <saeedm@...lanox.com>
Cc:     Eric Dumazet <eric.dumazet@...il.com>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>
Subject: Re: [Patch net] mlx5: fixup checksum for ethernet padding

On Tue, Nov 27, 2018 at 5:11 PM Saeed Mahameed <saeedm@...lanox.com> wrote:
>
> On Tue, 2018-11-27 at 16:07 -0800, Cong Wang wrote:
> > On Tue, Nov 27, 2018 at 3:48 PM Eric Dumazet <eric.dumazet@...il.com>
> > wrote:
> > > The bug here is that mlx5 csum only includes the data in IP frame.
> > >
> > > I would simply force skb->ip_summed to CHECKSUM_NONE if any padding
> > > is detected.
> > >
>
> Totally agree, let's just skip csum completes for very small packets
> ( < ETH_ZLEN ).

That is my first idea in my mind, but you know we still have to parse IP header
to detect packets < ETH_ZLEN. Essentially same work, only saves a few adds
in csum_add(). ;)