Re: jail exec.clean busted in 12?

On Tue, Sep 11, 2018 at 06:55:56PM -0400, Shawn Webb wrote:
> On Tue, Sep 11, 2018 at 03:58:02PM -0400, Michael W. Lucas wrote:
> > 
> > Hi,
> > 
> > storm~;uname -a
> > FreeBSD storm 12.0-ALPHA4 FreeBSD 12.0-ALPHA4 #10 r338496: Thu Sep  6 12:29:00 EDT 2018     root_at_storm:/usr/obj/usr/src/amd64.amd64/sys/GENERIC  amd64
> > 
> > It appears that exec.clean is busted. Here's my jail.conf:
> > 
> > ---
> > 
> > $j="/jail";
> > path="$j/$name";
> > host.hostname="$name.mwl.io";
> > 
> > mount.devfs;
> > exec.clean=0;
> > exec.start="sh /etc/rc";
> > exec.stop="sh /etc/rc.shutdown";
> > 
> > loghost {
> >   ip4.addr="203.0.113.231";
> >   allow.raw_sockets=1;
> >   jid=99;
> > }
> > 
> > logdb {
> >   host.hostname="logdb.mwl.io";
> >   ip4.addr="203.0.113.232";
> >   }
> > 
> > ---
> > 
> > exec.clean is not explicitly defined on the command line, but it's the
> > default, so it maybe shouldn't be?
> > 
> > storm~;jls -n
> > devfs_ruleset=0 nodying enforce_statfs=2 host=new ip4=disable ip6=disable jid=8 linux=new name=logdb osreldate=1200084 osrelease=12.0-ALPHA4 parent=0 path=/jail/logdb nopersist securelevel=-1 sysvmsg=disable sysvsem=disable sysvshm=disable vnet=inherit allow.nochflags allow.nomlock allow.nomount allow.mount.nodevfs allow.mount.nofdescfs allow.mount.nolinprocfs allow.mount.nonullfs allow.mount.noprocfs allow.mount.notmpfs allow.mount.nozfs allow.noquotas allow.noraw_sockets allow.reserved_ports allow.set_hostname allow.nosocket_af allow.nosysvipc children.cur=0 children.max=0 cpuset.id=6 host.domainname="" host.hostid=0 host.hostname=logdb.mwl.io host.hostuuid=00000000-0000-0000-0000-000000000000 ip4.addr=203.0.113.232 ip4.saddrsel ip6.addr= ip6.saddrsel linux.osname=Linux linux.osrelease=2.6.32 linux.oss_version=198144
> > devfs_ruleset=0 nodying enforce_statfs=2 host=new ip4=disable ip6=disable jid=99 linux=new name=loghost osreldate=1200084 osrelease=12.0-ALPHA4 parent=0 path=/jail/loghost nopersist securelevel=-1 sysvmsg=disable sysvsem=disable sysvshm=disable vnet=inherit allow.nochflags allow.nomlock allow.nomount allow.mount.nodevfs allow.mount.nofdescfs allow.mount.nolinprocfs allow.mount.nonullfs allow.mount.noprocfs allow.mount.notmpfs allow.mount.nozfs allow.noquotas allow.raw_sockets allow.reserved_ports allow.set_hostname allow.nosocket_af allow.nosysvipc children.cur=0 children.max=0 cpuset.id=7 host.domainname="" host.hostid=0 host.hostname=loghost.mwl.io host.hostuuid=00000000-0000-0000-0000-000000000000 ip4.addr=203.0.113.231 ip4.saddrsel ip6.addr= ip6.saddrsel linux.osname=Linux linux.osrelease=2.6.32 linux.oss_version=198144
> > 
> > Anyway, I found this by:
> > 
> > # jexec loghost env
> > HOME=/home/mwlucas
> > PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/home/mwlucas/bin
> > TERM=xterm
> > LC_COLLATE=C
> > LANG=en_US.UTF-8
> > SSH_CLIENT=203.0.113.70 59076 22
> > SSH_CONNECTION=203.0.113.70 59076 203.0.113.50 22
> > SSH_TTY=/dev/pts/2
> > SSH_AUTH_SOCK=/tmp/ssh-ZfvZOatcsu/agent.60492
> > LC_CTYPE=en_US.ISO-8859-1
> > MAIL=/var/mail/root
> > ...
> > 
> > I'm highly confident my SSH environment shouldn't be in the jail. Yes,
> > it goes away if I add -l, but my (admittedly sketchy) reading of the
> > jexec source says that jexec handles stripping the environment before
> > running the command.
> > 
> > Even if I start it the hard way (from a discussion at
> > https://github.com/iocage/iocage/issues/610)
> > 
> > storm~;jail -c path=/jail/loghost/ host.hostname=loghost exec.clean=1 persist
> > storm~;jls
> >    JID  IP Address      Hostname                      Path
> >      9                  loghost                       /jail/loghost
> >      
> > storm~;jexec 9 env | grep -i ssh
> > SSH_CLIENT=203.0.113.70 59076 22
> > SSH_CONNECTION=203.0.113.70 59076 203.0.113.50 22
> > SSH_TTY=/dev/pts/2
> > SSH_AUTH_SOCK=/tmp/ssh-ZfvZOatcsu/agent.60492
> > storm~;
> > 
> > Any ideas?
> 
> Hey Michael,
> 
> It appears the jail.exec option is for jail(8) only.

Ah, okay. Thanks. Not obvious, but makes sense.

(So you can run your dirty environment in the jail through jexec? Cool.)

==ml

> You need to pass
> the -l option to jexec(8) to sanitize the environment.
> 
> Thanks,
> 
> -- 
> Shawn Webb
> Cofounder and Security Engineer
> HardenedBSD
> 
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-- 
Michael W. Lucas 	https://mwl.io/
author of: Absolute OpenBSD, SSH Mastery, git commit murder,
Immortal Clay, PGP & GPG, Absolute FreeBSD, etc, etc, etc...