netdev - Re: [PATCH net-next 1/2] tcp: remove per-destination timestamp cache

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]

Message-ID: <1489618741.28631.172.camel@edumazet-glaptop3.roam.corp.google.com>
Date:   Wed, 15 Mar 2017 15:59:01 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     David Miller <davem@...emloft.net>
Cc:     soheil.kdev@...il.com, netdev@...r.kernel.org, soheil@...gle.com,
        edumazet@...gle.com, ncardwell@...gle.com, ycheng@...gle.com,
        lvml@....de, fw@...len.de
Subject: Re: [PATCH net-next 1/2] tcp: remove per-destination timestamp cache

On Wed, 2017-03-15 at 15:40 -0700, David Miller wrote:
> From: Soheil Hassas Yeganeh <soheil.kdev@...il.com>
> Date: Wed, 15 Mar 2017 16:30:45 -0400
> 
> > Note that this cache was already broken for caching timestamps of
> > multiple machines behind a NAT sharing the same address.
> 
> That's the documented, well established, limitation of time-wait
> recycling.
> 
> People who enable it, need to consider this issue.
> 
> This limitation of the feature does not give us a reason to break the
> feature even further as a matter of convenience, or to remove it
> altogether for the same reason.
> 
> Please, instead, fix the bug that was introduced.
> 
> Thank you.

You mean revert Florian nice patches ?

This would kill timestamps randomization, and thus prevent some
organizations to turn TCP timestamps on.

TCP timestamps are more useful than this obscure tw_recycle thing that
is hurting innocent users.