Date: Thu, 28 Sep 2000 11:06:37 -0400 (EDT) From: Robert Watson <rwatson@freebsd.org> To: Paulo Fragoso <paulo@nlink.com.br> Cc: freebsd-security@freebsd.org Subject: Re: Jail + PostgreSQL Message-ID: <Pine.NEB.3.96L.1000928110030.7124B-100000@fledge.watson.org> In-Reply-To: <Pine.BSF.4.10.10009281013250.83565-100000@mirage.nlink.com.br>
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On Thu, 28 Sep 2000, Paulo Fragoso wrote:
> If we kill all postgres in all jails and we start postgresql manually on
> frist jail after this we start postgresql on second jail all work fine.
I wasn't clear from your description as to the configuration. I generally
thing of jails in the following kind of diagram:
+------------------------------------------+
| The host environment |
| |
| +-------+ +-------+ |
| | Jail1 | | Jail2 | |
| +-------+ +-------+ |
+------------------------------------------+
This is intended to reflect that while jail's are logically partitioned,
they're all subsets of the host environment, and that therefore there can
be interactions between the host and jail environments. For example, the
reason the jail(8) man page recommends not running inetd/sendmail/sshd/etc
in the host environment without configuration modifications is the
following: a daemon that binds INADDR_ANY in a jail is limited to that
jail's IP address, whereas a daemon in the host environment will listen on
any IP not specifically bound by an application (i.e., one in a jail).
this means that sendmail will listen on jail IPs if those jails are not
running sendmail -- undesirable :-). So my questions below are pointed at
determining if this is a host interaction like that, or if it is an
inter-jail interaction.
In which locations in this diagram are you running postgresql? It sounded
like a pgsql in Jail1, and a pgsql in Jail2, but was there also one in the
host environment?
> Are there any problem with shared memory using jail? Is this a security
> problem?
It may be, and I don't know because I didn't write this code, that all
jails share the same SysV SHM namespace. If that is the case, it needs to
be fixed, and could be a security problem if you run applications using
SysV SHM between jails. However, it could also be a host vs. jail issue,
if you are starting a pgsql in the host environment, which might interfere
with the ones in jail. You note that re-running them in the jails makes
them start fine -- is this an indication that you had one in the host
environment? A concise timeline concerning the starting, stopping, and
errors, as well as jail starting events, would be useful. I admit to
having never tried to run postgresql in a jail, but it seems like a useful
thing to do :-).
Robert N M Watson
robert@fledge.watson.org http://www.watson.org/~robert/
PGP key fingerprint: AF B5 5F FF A6 4A 79 37 ED 5F 55 E9 58 04 6A B1
TIS Labs at Network Associates, Safeport Network Services
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