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From:   Eric Dumazet <edumazet@google.com>
Date:   Thu, 10 Dec 2020 15:32:12 +0100
Message-ID: <CANn89iK=kMSkT771iL0dybnWisXr9FWW-bffa5KB+McBYrxx4g@mail.gmail.com>
Subject: Re: [PATCH 4.4 15/39] geneve: pull IP header before ECN decapsulation
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, stable@vger.kernel.org,
        syzbot <syzkaller@googlegroups.com>,
        Jakub Kicinski <kuba@kernel.org>
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On Thu, Dec 10, 2020 at 3:26 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> From: Eric Dumazet <edumazet@google.com>
>
> IP_ECN_decapsulate() and IP6_ECN_decapsulate() assume
> IP header is already pulled.
>
> geneve does not ensure this yet.
>
> Fixing this generically in IP_ECN_decapsulate() and
> IP6_ECN_decapsulate() is not possible, since callers
> pass a pointer that might be freed by pskb_may_pull()
>
> syzbot reported :
>

Note that we had to revert this patch, so you can either scratp this
backport, or make sure to backport the revert.

Thanks !