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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!spool.mu.edu!uwm.edu!news-peer.gsl.net!news.gsl.net!newsfeed.internetmci.com!in1.uu.net!EU.net!news2.EUnet.fr!newsbr.eunet.fr!usenet From: Frederic.Marand@osinet.fr (Frederic MARAND) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Why chown(2) is privileged? Date: Sat, 26 Oct 1996 08:49:05 GMT Organization: Groupe SEDI / Agorus SA / OSI SARL Lines: 39 Message-ID: <54smhh$9ib@newsbr.eunet.fr> References: <CANDY.96Oct24222129@xxx.fct.kgc.co.jp> <DzsJK6.2p8@zorch.SF-Bay.ORG> NNTP-Posting-Host: 193.107.196.155 X-Newsreader: Forte Free Agent 1.0.82 scott@zorch.sf-bay.org (Scott Hazen Mueller) wrote: >>Why does BSD disallow non super-user to transfer ownership of files to the >>others? >So non super-users cannot bypass the quota system by transferring file >ownership to other users, e.g. bin. > \scott More precisely, why would anyone bother ? The quota system is implemented but actually non-operating on several commercial unixes. A reason given by HP when they first introduced the "chown" privilege in HP-UX in 86 (release 5.18, I guess) was related to billing. Machines at this time were still expensive, and so was disk space, so users paying for disk occupation could reduce their bill by the simple sequence: chmod 777 myfile chgrp wheel myfile chown root myfile This way, files would be found to belong to root and not be charged to the user, who could however regain full ownership by another simple sequence: cat myfile > myotherfile rm myfile I think there are also some real security-related implications, but I won't delve on these. ------------------------- Frederic G. MARAND Agorus SA / OSI SARL Frederic.Marand@osinet.fr -------------------------