From owner-freebsd-fs Wed Jun 19 8: 4:18 2002 Delivered-To: freebsd-fs@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by hub.freebsd.org (Postfix) with ESMTP id 1481637B406 for ; Wed, 19 Jun 2002 08:04:08 -0700 (PDT) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.3/8.12.2) with ESMTP id g5JF2GIj012748; Wed, 19 Jun 2002 17:02:21 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Martin Faxer Cc: freebsd-fs@FreeBSD.ORG Subject: Re: a bunch of questions In-Reply-To: Your message of "Wed, 19 Jun 2002 16:41:11 +0200." <20020619144111.GA1352@lockdown.spectrum.fearmuffs.net> Date: Wed, 19 Jun 2002 17:02:16 +0200 Message-ID: <12747.1024498936@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In message <20020619144111.GA1352@lockdown.spectrum.fearmuffs.net>, Martin Faxe r writes: >hello! > >i'm trying to make some sense of vfs and here comes a mail with >basically (as the subject says) a bunch of questions: > >1) why is it preferred to do the permissions checking in the > actual file system specific code instead of vfs_[n]mount()? Because not all filesystems need or indeed want the same permissions checks. Some filesystems don't even have a device (DEVFS, procfs, unionfs etc) >2) in the statfs() code the f_fsid is zeroed out in the !superuser > case. after some searching and cross-checking with OpenBSD i'm > lead to believe that this is because of a potential NFS insecurity > if any user is able to see the f_fsid. does anybody know more > about this ? can a check be added like: I belive it is because of the NFS. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message