Re: sshd failing in jail

Am 24.08.2009 um 21:33 schrieb Peter Jeremy:

> I am attempting to build an i386 jail on an amd64 box to build
> packages for my netbook.  The host is running -current from just over
> two weeks ago and the jail is -current from early June.  The jail was
> built by doing a dump|restore of my netbook and then tweaking various
> config files to give it a new identity.  The jail's devfs is using
> "devfsrules_jail" from /etc/default/devfs.rules.
>
> The jail starts OK but when I attempt to ssh into it, I just get
> "Connection closed by <jail IP address>".  Adding debugging on the
> child, I see that it occurs immediately following:
> "debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY".
>
> Looking at a ktrace of the jailed sshd, the problem is inside the
> privilege separation child.  When I turned off privilege separation, I
> can log into the jail.  When I added a syslog socket inside the jailed
> chroot and left privilege separation enabled, I got:
> Aug 24 19:04:40 server sshd[70809]: error: buffer_put_bignum2_ret:  
> BN too small
> Aug 24 19:04:40 server sshd[70809]: fatal: buffer_put_bignum2:  
> buffer error
> Unfortunately, buffer_put_bignum2() is called from a number of  
> locations
> so the actual problem is not clear.
>
> Looking at google doesn't turn up anything useful.
>
> Does anyone have any suggestions?

I had similar symptoms during a recent make world.  Finishing  
installworld in the jails and rebooting made it all work again, so I  
did not investigate further.


Stefan

-- 
Stefan Bethke <stb_at_lassitu.de>   Fon +49 151 14070811