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From:   Xie He <xie.he.0141@gmail.com>
Date:   Thu, 8 Oct 2020 16:40:36 -0700
Message-ID: <CAJht_EOMQRKWfwhfqwXB3RYA1h463q43ycNjJmaGZm6RS65QGA@mail.gmail.com>
Subject: Re: [Patch net] ip_gre: set dev->hard_header_len properly
To:     Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc:     Cong Wang <xiyou.wangcong@gmail.com>,
        Network Development <netdev@vger.kernel.org>,
        syzbot <syzbot+4a2c52677a8a1aa283cb@syzkaller.appspotmail.com>,
        William Tu <u9012063@gmail.com>
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On Thu, Oct 8, 2020 at 2:54 PM Xie He <xie.he.0141@gmail.com> wrote:
>
> OK. If the t->encap_hlen header needs to be placed before the GRE
> header, then I think the ipgre_header function should leave some space
> before the GRE header to place the t->encap_hlen header, rather than
> leaving space after the GRE header.

I found another possible issue. Shouldn't we update hard_header_len
every time t->tun_hlen and t->hlen are updated in ipgre_link_update?