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From: tmh@prosun.first.gmd.de (Thomas Hoberg)
Newsgroups: comp.unix.sysv386
Subject: Re: NFS-/etc/exports
Keywords: nfs
Message-ID: <681@bigfoot.first.gmd.de>
Date: 23 May 91 15:05:04 GMT
References: <223@gouche.UUCP>
Sender: news@bigfoot.first.gmd.de
Reply-To: tmh@prosun.first.gmd.de (Thomas Hoberg)
Organization: GMD-FIRST, D-1000 Berlin 10
Lines: 30

In article <223@gouche.UUCP>, grant@gouche (Grant J. Munsey) writes:
|> 
|> I have ISC 2.1 using NFS. I want to publish a file system such that
|> a remote machine can become root wrt the file system. I notice in some
|> NFS implementations the file /etc/exports is where you put instructions
|> to NFS to allow this. In the NFS doc from Interactive it doesn't mention
|> anything. Anyoue know the skinny on this?

ISC or rather the Lachman Ass. version of NFS doesn't support this directly.
I wrote a small program (sorry don't have it here) that used 'nm' to find the
address of NOBODY in the kernel, did a seek, read and write on /dev/kmem (or
was it /dev/mem ?) to patch NOBODY (maxint - 2 by default) to 0 (root). Root
accesses are mapped to the UID NOBODY by default (for security reasons). This
is very risky, though, because if a file system is exported to a machine with
a user that is not know by the exporting system, that user will get mapped to
NOBODY, too, meaning any unknown user will have *root* access, too. BTW, NOBODY
has to be patched on the exporting system.

|> ----
|> Grant Munsey, Mainticore, Inc. (408) 733-3838
|> grant@gouche.portal.com  or  decwrl!apple!portal!gouche!grant

-- tom
----
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