netdev - Re: [PATCH 3/3] [RFC] TCP syncookies: only allow 3 MSS values by default to mitigate spoofing attacks

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, 16 Aug 2013 23:31:01 +0200
From:	Florian Westphal <fw@...len.de>
To:	Jiri Bohac <jbohac@...e.cz>
Cc:	Jakob Lell <jakob@...oblell.com>, netdev@...r.kernel.org,
	davem@...emloft.net
Subject: Re: [PATCH 3/3] [RFC] TCP syncookies: only allow 3 MSS values by
 default to mitigate spoofing attacks

Jiri Bohac <jbohac@...e.cz> wrote:
> Rationale for the new values
> - most packets are (1500 - headers); (1450 - headers) is not a huge waste and
>   prevents fallback to much lower values

Still, 1410 seems weird.

> - clients will rarely send MSS below 536, so that's a safe fallback

Can you elaborate?
You say 'is a safe fallback', yet it is removed in the patch?

> - we need to keep the minimum (64)

Why?
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html