netdev - Re: [PATCH net-next] udp: avoid refcount_t saturation in __udp_gso

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Date:   Thu, 10 May 2018 23:30:17 -0400
From:   Willem de Bruijn <willemdebruijn.kernel@...il.com>
To:     Eric Dumazet <edumazet@...gle.com>
Cc:     "David S . Miller" <davem@...emloft.net>,
        netdev <netdev@...r.kernel.org>,
        Eric Dumazet <eric.dumazet@...il.com>,
        Willem de Bruijn <willemb@...gle.com>,
        Alexander Duyck <alexander.h.duyck@...el.com>
Subject: Re: [PATCH net-next] udp: avoid refcount_t saturation in __udp_gso_segment()

On Thu, May 10, 2018 at 10:07 PM, Eric Dumazet <edumazet@...gle.com> wrote:
> For some reason, Willem thought that the issue we fixed for TCP
> in commit 7ec318feeed1 ("tcp: gso: avoid refcount_t warning from
> tcp_gso_segment()") was not relevant for UDP GSO.
>
> But syzbot found its way.

[..]

> Fixes: ad405857b174 ("udp: better wmem accounting on gso")
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Cc: Willem de Bruijn <willemb@...gle.com>
> Cc: Alexander Duyck <alexander.h.duyck@...el.com>
> Reported-by: syzbot <syzkaller@...glegroups.com>

Acked-by: Willem de Bruijn <willemb@...gle.com>

Thanks Eric. Yep, I was naive here. I am quite curious what kind of
gso packet syzkaller was able to cook that exceeds the truesize
of its segments.