From owner-freebsd-hackers@FreeBSD.ORG  Thu Oct  7 19:05:02 2010
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 5F783106566B;
	Thu,  7 Oct 2010 19:05:02 +0000 (UTC) (envelope-from jh@FreeBSD.org)
Received: from gw01.mail.saunalahti.fi (gw01.mail.saunalahti.fi
	[195.197.172.115])
	by mx1.freebsd.org (Postfix) with ESMTP id 190F28FC12;
	Thu,  7 Oct 2010 19:05:01 +0000 (UTC)
Received: from a91-153-123-205.elisa-laajakaista.fi
	(a91-153-123-205.elisa-laajakaista.fi [91.153.123.205])
	by gw01.mail.saunalahti.fi (Postfix) with SMTP id 65FC1151700;
	Thu,  7 Oct 2010 21:45:50 +0300 (EEST)
Date: Thu, 7 Oct 2010 21:45:49 +0300
From: Jaakko Heinonen <jh@FreeBSD.org>
To: Alexander Best <arundel@freebsd.org>
Message-ID: <20101007184549.GA76070@a91-153-123-205.elisa-laajakaista.fi>
References: <20101005235054.GA45827@freebsd.org>
	<AANLkTi=sA4GP=B61tbEmG6B0CYcET=dCFMJByoS_5=yi@mail.gmail.com>
	<20101006173522.GA92402@freebsd.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20101006173522.GA92402@freebsd.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: freebsd-hackers@freebsd.org, Garrett Cooper <gcooper@FreeBSD.org>
Subject: Re: issue with unsetting 'arch' flag
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Oct 2010 19:05:02 -0000

On 2010-10-06, Alexander Best wrote:
> $ sudo rm -d /tmp/chflags.XXXXXX
> $ tmpfile=`mktemp /tmp/chflags.XXXXXX`
> $ sudo chflags arch $tmpfile
> $ chflags noarch $tmpfile
> 
> is what's causing the problem. the last chflags call should fail, but it
> doesn't.

Here is a patch for UFS:

%%%
Index: sys/ufs/ufs/ufs_vnops.c
===================================================================
--- sys/ufs/ufs/ufs_vnops.c	(revision 213507)
+++ sys/ufs/ufs/ufs_vnops.c	(working copy)
@@ -556,6 +556,9 @@ ufs_setattr(ap)
 			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
 				return (EPERM);
+			if ((ip->i_flags & SF_SETTABLE) !=
+			    (vap->va_flags & SF_SETTABLE))
+ 				return (EPERM);
 			ip->i_flags &= SF_SETTABLE;
 			ip->i_flags |= (vap->va_flags & UF_SETTABLE);
 			DIP_SET(ip, i_flags, ip->i_flags);
%%%

The patch has a potential to break something if someone assumes that
non-super-user can modify UF_SETTABLE flags with the SF_SETTABLE part
set to zero. However with a quick peek this seems to be what NetBSD
does.

-- 
Jaakko