Date: Fri, 30 Mar 2012 11:57:29 -0700 From: Adrian Chadd <adrian@freebsd.org> To: "Julian H. Stacey" <jhs@berklix.com> Cc: arch@freebsd.org Subject: Re: Should standard binaries & directories revert from uid=root to bin ? Message-ID: <CAJ-Vmon=YKcW6Osn2TXcJDbNH1B0xLapL-fTz0myGanHdPW4Yw@mail.gmail.com> In-Reply-To: <201203301516.q2UFG3ee013758@fire.js.berklix.net> References: <201203301516.q2UFG3ee013758@fire.js.berklix.net>
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hi, because id=3D0 defaults to being squashed via nfs. But if you have a filesystem full of uid=3Dbin/gid=3Dbin binaries, a slightly insecure NFS setup would allow NFS clients to simply set their uid=3Dbin and change these binaries. :-) Adrian On 30 March 2012 08:16, Julian H. Stacey <jhs@berklix.com> wrote: > Hi arch@ > Time was, (& I can go back over 25 years here, but more recently too :-) > When standard Unix non SUID executables such as wc would be UID=3Dbin, > GID=3Dbin, & not root. =A0Ditto bin/ & lib/ etc directories. > > One advantage was: > =A0Anything that showed up with ls -l as UID=3D0 was either a SUID > =A0special, known to the admin's eye, or some administrative dropping, > =A0mistakenly created by someone logged in as root, to be reviewed/ > =A0regenerated/ deleted. > > Now all is UID=3D0. =A0Why ? What advantage did it bring ? > > Obviously some SUID & SGID executables need 0 (some could need just bin!) > but most files & directories do not need UID 0. > > BTW, How I noticed this : > =A0I was tracing why > =A0 =A0 =A0 =A0/usr/sbin/sshd -d -d -d -D > =A0was erroring: > =A0 =A0 =A0 =A0debug3: secure_filename: checking '/.amd_mnt/sshd_host/ad4= s1/usr1/home' > =A0 =A0 =A0 =A0Authentication refused: bad ownership or modes for directo= ry > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 /.amd_mnt/sshd_host/ad4s1/usr1/home > =A0just because my ~/.ssh was symbolicaly linked via AMD+NFS mounted on a= nother > =A0host, & there an intermediate directory was owned by bin & not root, > =A0 =A0 =A0 =A0ls -la /host/sshd_host/ad4s1/usr1/home > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0drwxr-xr-x =A018 bin =A0 =A0 bin =A0 =A0 = =A0 512 Mar =A06 11:56 ./ > =A0so I had to > =A0 =A0 =A0 =A0chown root:wheel /ad4s1/usr1/home > =A0Just to satisfy sshd being pointlessly strict, as directory was 755. > > So we have sshd that's pointlessly strict, & ownerships that seem > to have near all lost their precision. A funny combo ;-) > > Might others tackle the generic over use of root ? > If so I could create a patch to send-pr ssh =A0? > (but as ssh is an import, maybe just report & not [yet?] patch ?) > > Cheers, > Julian > -- > Julian Stacey, BSD Unix Linux C Sys Eng Consultants Munich http://berklix= .com > =A0Reply below not above, cumulative like a play script, & indent with ">= ". > =A0Format: Plain text. Not HTML, multipart/alternative, base64, quoted-pr= intable. > =A0 =A0 =A0 =A0Mail from @yahoo dumped @berklix. =A0http://berklix.org/ya= hoo/ > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org"
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