From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net 0/5] tcp: more robust ooo handling
Date: Mon, 23 Jul 2018 12:03:17 -0700 (PDT)
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Cc: juha-matti.tilli@iki.fi, ycheng@google.com, soheil@google.com,
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From: Eric Dumazet <edumazet@google.com>
Date: Mon, 23 Jul 2018 09:28:16 -0700

> Juha-Matti Tilli reported that malicious peers could inject tiny
> packets in out_of_order_queue, forcing very expensive calls
> to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for
> every incoming packet.
> 
> With tcp_rmem[2] default of 6MB, the ooo queue could
> contain ~7000 nodes.
> 
> This patch series makes sure we cut cpu cycles enough to
> render the attack not critical.
> 
> We might in the future go further, like disconnecting
> or black-holing proven malicious flows.

Sucky...

It took me a while to understand the sums_tiny logic, every
time I read that function I forget that we reset all of the
state and restart the loop after a coalesce inside the loop.

Series applied, and queued up for -stable.

Thanks!