netdev - Re: [Bugme-new] [Bug 36122] New: New cache learned PMTU information in inetpeer causes ssh to fail when tunneled via an IPSEC VPN

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>] [day] [month] [year] [list]

Date:	Mon, 6 Jun 2011 13:48:41 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	netdev@...r.kernel.org
Cc:	bugzilla-daemon@...zilla.kernel.org,
	bugme-daemon@...zilla.kernel.org, blueness@...too.org,
	kernel@...too.org
Subject: Re: [Bugme-new] [Bug 36122] New: New cache learned PMTU information
 in inetpeer causes ssh to fail when tunneled via an IPSEC VPN


(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Sat, 28 May 2011 21:50:32 GMT
bugzilla-daemon@...zilla.kernel.org wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=36122
> 
>                URL: http://bugs.gentoo.org/show_bug.cgi?id=369025
>            Summary: New cache learned PMTU information in inetpeer causes
>                     ssh to fail when tunneled via an IPSEC VPN
>            Product: Networking
>            Version: 2.5
>     Kernel Version: 2.6.39
>           Platform: All
>         OS/Version: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: IPV4
>         AssignedTo: shemminger@...ux-foundation.org
>         ReportedBy: blueness@...too.org
>                 CC: kernel@...too.org
>         Regression: No
> 
> 
> When trying to ssh from a box running 2.6.39 on one private subnet to another
> box on another private subnet via an IPSEC vpn, ssh freezes and times out at:
> 
>    debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
> 
> This was traced down to commit 2c8cec5c10bced2408082a6656170e74ac17231c.
> 
> This type of error is known to occur when there is fragmentation due to
> mismatched mtu's which the commit addresses.
> 
> Notice the problem does not occur when ssh-ing directly, ie not via an IPSEC
> tunnel.  I have not tested if other tunnels are affected.
> 
> Please see the downstream bug for more details.
> 

--
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