NFS-/etc/exports

Thomas Hoberg tmh at prosun.first.gmd.de
Fri May 24 01:05:04 AEST 1991


In article <223 at gouche.UUCP>, grant at 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 at gouche.portal.com  or  decwrl!apple!portal!gouche!grant

-- tom
----
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