Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261797AbVEEVCx (ORCPT ); Thu, 5 May 2005 17:02:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261905AbVEEVCx (ORCPT ); Thu, 5 May 2005 17:02:53 -0400 Received: from turing-police.cirt.vt.edu ([128.173.54.129]:65029 "EHLO turing-police.cirt.vt.edu") by vger.kernel.org with ESMTP id S261797AbVEEVCu (ORCPT ); Thu, 5 May 2005 17:02:50 -0400 Message-Id: <200505052102.j45L2kI7013191@turing-police.cc.vt.edu> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.1-RC3 To: Xin Zhao Cc: linux-kernel@vger.kernel.org Subject: Re: does e2fsprogs needs to invoke file system related system calls? In-Reply-To: Your message of "Thu, 05 May 2005 16:49:33 EDT." <4ae3c1405050513493b5a1b88@mail.gmail.com> From: Valdis.Kletnieks@vt.edu References: <4ae3c1405050513493b5a1b88@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1115326966_5123P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Thu, 05 May 2005 17:02:46 -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1584 Lines: 39 --==_Exmh_1115326966_5123P Content-Type: text/plain; charset=us-ascii On Thu, 05 May 2005 16:49:33 EDT, Xin Zhao said: > does e2fsprogs needs to invoke file system related system calls? Which calls do you mean? I suspect that for the most part, it's doing read/write/etc to the *underlying medium* - for instance, mkfs.ext3 can't use calls related to the *file system* because it's not mounted yet (it doesn't even *exist* yet). > The reason I want to ask this question is to know whether we can > bypass the system call monitoring based access control with e2fsprogs. It's been known since the Unix V7 days and even earlier that having read/write access to the underlying /dev/hd-whatever partition was able to bypass file permissions on the file system built on that partition. Of course, write access is at your own risk, as there's no easy/clean way to ensure that the kernel doesn't have an in-core copy that doesn't match what you wrote (as everybody who's run fsck on a live file system can testify ;) --==_Exmh_1115326966_5123P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFCeon2cC3lWbTT17ARAnsEAJ9Mw3AH+0CPFdiUwTW9e+sRfngTHgCgvO3h 4kWpyM7vWjiW6qJ41dzVJsk= =hfqc -----END PGP SIGNATURE----- --==_Exmh_1115326966_5123P-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/