From: Willy Tarreau <w@1wt.eu>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Maciej Zenczykowski <maze@google.com>
Subject: Re: [PATCH net] ipv6: tcp: drop silly ICMPv6 packet too big messages
Date: Wed, 7 Jul 2021 17:59:30 +0200 [thread overview]
Message-ID: <20210707155930.GE1978@1wt.eu> (raw)
In-Reply-To: <20210707154630.583448-1-eric.dumazet@gmail.com>
Hi Eric,
On Wed, Jul 07, 2021 at 08:46:30AM -0700, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> While TCP stack scales reasonably well, there is still one part that
> can be used to DDOS it.
>
> IPv6 Packet too big messages have to lookup/insert a new route,
> and if abused by attackers, can easily put hosts under high stress,
> with many cpus contending on a spinlock while one is stuck in fib6_run_gc()
Just thinking loud, wouldn't it make sense to support randomly dropping
such packets on input (or even better rate-limit them) ? After all, if
a host on the net feels like it will need to send one, it will surely
need to send a few more until one is taken into account so it's not
dramatic. And this could help significantly reduce their processing cost.
Willy
next prev parent reply other threads:[~2021-07-07 15:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 15:46 [PATCH net] ipv6: tcp: drop silly ICMPv6 packet too big messages Eric Dumazet
2021-07-07 15:59 ` Willy Tarreau [this message]
2021-07-07 16:06 ` Eric Dumazet
2021-07-07 16:15 ` Willy Tarreau
2021-07-07 16:25 ` Eric Dumazet
2021-07-07 16:27 ` Willy Tarreau
2021-07-07 16:30 ` Eric Dumazet
2021-07-07 16:30 ` Maciej Żenczykowski
2021-07-07 22:25 ` Martin KaFai Lau
2021-07-08 5:52 ` Eric Dumazet
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