netdev - Re: [PATCH v2 net-next 11/11] tcp: rate limit ACK sent by SYN

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 1 Apr 2016 12:05:20 -0400
From:	Neal Cardwell <ncardwell@...gle.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>,
	Tom Herbert <tom@...bertland.com>,
	Willem de Bruijn <willemb@...gle.com>,
	Maciej Żenczykowski <maze@...gle.com>
Subject: Re: [PATCH v2 net-next 11/11] tcp: rate limit ACK sent by SYN_RECV
 request sockets

On Fri, Apr 1, 2016 at 11:52 AM, Eric Dumazet <edumazet@...gle.com> wrote:
> Attackers like to use SYNFLOOD targeting one 5-tuple, as they
> hit a single RX queue (and cpu) on the victim.
>
> If they use random sequence numbers in their SYN, we detect
> they do not match the expected window and send back an ACK.
>
> This patch adds a rate limitation, so that the effect of such
> attacks is limited to ingress only.
>
> We roughly double our ability to absorb such attacks.

Thanks, Eric!

Acked-by: Neal Cardwell <ncardwell@...gle.com>

neal