From owner-freebsd-current  Sat Feb 27  8:17:46 1999
Delivered-To: freebsd-current@freebsd.org
Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.26.10.9])
	by hub.freebsd.org (Postfix) with ESMTP id 2563714FB3
	for <current@FreeBSD.ORG>; Sat, 27 Feb 1999 08:17:43 -0800 (PST)
	(envelope-from bde@godzilla.zeta.org.au)
Received: (from bde@localhost)
	by godzilla.zeta.org.au (8.8.7/8.8.7) id DAA18010;
	Sun, 28 Feb 1999 03:17:20 +1100
Date: Sun, 28 Feb 1999 03:17:20 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199902271617.DAA18010@godzilla.zeta.org.au>
To: asmodai@wxs.nl, dfr@nlsystems.com
Subject: Re: Really! strange uid value
Cc: current@FreeBSD.ORG, mi@kot.ne.mediaone.net, sthaug@nethelp.no
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

>> >> =1 drwxr-xr-x  3 4294967294  wheel  - 512 Feb 15 21:09 aout/
>> >> =
>> >> =funny, the same value. There is something left out very fundamentally
>> >> =somewhere.
>> >> 
>> >> Just FYI. This number is 0xFFFFFFFE in hex... A search for this number
>> >> through the sources does not bring anything under NFS itself, though the
>> >> following may give a clue:
>> > 
>> > Remember that the "nobody" user is uid 65534 (0xfffe). The signed
>> > extension of this to 32 bits is 0xfffffffe. Maybe you're seeing uid 0
>> > being translated to 65534 (due to NFS) and then sign extended.
>> 
>> Could be, but that is still not correct behaviour as far as my knowledge
>> goes. It should not get sign extended IMHO. Am I correct in assuming this
>> (call to the more knowledgeable ones)?
>
>Do you have a simple repeatable test?  What OS is the server running?

FreeBSD server, FreeBSD client, nfsv3:

	# cd world_writable_nfs_mounted_directory_which_shouldnt_exist
	# cat
	^\
	# ls -l cat.core
	-rw-------  1 4294967294  wheel  225280 Feb 28 03:06 cat.core

4294967294 is just the default mapped uid for root.  It is (uid_t)-2.
See mountd sources.  It has nothing to do with user nobody or 65534,
except possibly on buggy clients that silently truncate it mod 65536.
Perhaps it is a bug to use (uid_t)-2 instead of 65534.  For clients
with only 16-bit uid_t's you would want to keep all uids on the
server < 65536.

Bruce


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message