Date: Wed, 6 Oct 2010 10:09:21 -0700 From: Garrett Cooper <gcooper@FreeBSD.org> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: issue with unsetting 'arch' flag Message-ID: <AANLkTi=sA4GP=B61tbEmG6B0CYcET=dCFMJByoS_5=yi@mail.gmail.com> In-Reply-To: <20101005235054.GA45827@freebsd.org> References: <20101005235054.GA45827@freebsd.org>
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On Tue, Oct 5, 2010 at 4:50 PM, Alexander Best <arundel@freebsd.org> wrote:
> hi there,
>
> i think the following example shows the problem better than a long explan=
ation:
>
> `touch ftest && chflags arch ftest && chflags -vv 0 ftest`.
> =A0^^non-root =A0 =A0 ^^root =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0^^non-root
>
> chflags claims to have cleared the 'arch' flag (which should be impossibl=
e as
> non-root user), but indeed has done nothing.
>
> i've tried the same with 'sappnd' and that works as can be expected.
>
> The issue was confirmed to exist in HEAD (me), stable/8 (pgollucc1, jpaet=
zel)
> and stable/7 (nox).
> On stable/6 it does NOT exist (jpaetzel). chflags properly fails with EPE=
RM.
Fails for me when I call the syscall directly, as I would expect,
and passes when I'm superuser:
$ ./test_chflags
(uid, euid) =3D (1000, 1000)
test_chflags: chflags: Operation not permitted
test_chflags: lchflags: Operation not permitted
$ sudo ./test_chflags
(uid, euid) =3D (0, 0)
According to my basic inspection in strtofflags
(.../lib/libc/gen/strtofflags.c), it works as well.
And last but not least, executing the commands directly on the CLI work=
:
$ tmpfile=3D`mktemp /tmp/chflags.XXXXXX`
$ chflags arch $tmpfile
chflags: /tmp/chflags.nQm1IL: Operation not permitted
$ rm $tmpfile
$ tmpfile=3D`mktemp /tmp/chflags.XXXXXX`
$ sudo chflags arch $tmpfile
$ sudo chflags noarch $tmpfile
$ rm $tmpfile
Your results may (but shouldn't) vary [unless your environment is
setup differently]...
Please note that I'm using UFS2 with SUJ... not all filesystems
support this (ext2/3/4? msdosfs? ZFS?), so I would be careful about
which filesystem you pick and whether or not there's a bug where it's
not properly identifying that the operation you're attempting to
perform is valid.
Thanks,
-Garrett
$ uname -a
FreeBSD bayonetta.local 9.0-CURRENT FreeBSD 9.0-CURRENT #9 r211309M:
Thu Aug 19 22:50:36 PDT 2010
root@bayonetta.local:/usr/obj/usr/src/sys/BAYONETTA amd64
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