From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261559AbVHEWoW (ORCPT ); Fri, 5 Aug 2005 18:44:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262013AbVHEWoV (ORCPT ); Fri, 5 Aug 2005 18:44:21 -0400 Received: from neveragain.de ([217.69.76.1]:23249 "EHLO hobbit.neveragain.de") by vger.kernel.org with ESMTP id S261968AbVHEWnl (ORCPT ); Fri, 5 Aug 2005 18:43:41 -0400 Date: Sat, 6 Aug 2005 00:42:33 +0200 From: Martin Loschwitz To: Andrew Morton Subject: Re: local DDOS? Kernel panic when accessing /proc/ioports Message-ID: <20050805224233.GA26096@minerva.local.lan> References: <20050805192628.GA24706@minerva.local.lan> <20050805214954.GA25533@minerva.local.lan> <20050805153344.5fb12313.akpm@osdl.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4Ckj6UjgE2iN1+kY" Content-Disposition: inline In-Reply-To: <20050805153344.5fb12313.akpm@osdl.org> User-Agent: Mutt/1.5.9i X-Greylist: Sender succeded SMTP AUTH authentication, not delayed by milter-greylist-1.4 (hobbit.neveragain.de [217.69.76.1]); Sat, 06 Aug 2005 00:43:41 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --4Ckj6UjgE2iN1+kY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 05, 2005 at 03:33:44PM -0700, Andrew Morton wrote: > Martin Loschwitz wrote: > > > > On Fri, Aug 05, 2005 at 03:40:26PM -0400, linux-os (Dick Johnson) wrote: > > >=20 > > > On Fri, 5 Aug 2005, Martin Loschwitz wrote: > > >=20 > > > > Hi folks, > > > > > > > > I just ran into the following problem: Having updated my box to 2.6= =2E12.3, > > > > I tried to start YaST2 and noticed a kernel panic (see below). Some= quick > > > > debugging brought the result that the kernel crashes while some use= r (not > > > > even root ...) tries to access /proc/ioports. Is this a known probl= em and > > > > if so, is a fix available? > > > > > > > > Ooops and ksymoops-output is attached. > > > > > > >=20 > > > This can happen if a module is unloaded that doesn't free its > > > resources! Been there, done that. > > >=20 > >=20 > > "This can happen" is not an acceptable explanation, I think. >=20 > It's a very accurate one though. >=20 > The most common cause of this bug is that some buggy kernel module has be= en > unloaded. It forgot to release its I/O region. When you later come along > to look in /proc/ioports the kernel goes to fetch information from the > memory which is "owned" by the module which isn't there any more. Crash. >=20 > So if you can identify which kernel module was loaded and then unloaded, > we'll fix it up. uhm -- well, okay, once again: If you boot knoppix with the "debug" argumen= t, it will start init but throw you on a very limited shell called "ash" right after that. At least the "cat" command is included in that shell, and lsmod= =20 is available as well. I am pretty sure that until that very early moment, not a single module has been unloaded -- infact, "rmmod" is not even called in the init script until that moment. The only modules loaded were: sbp2 ohci1394 usb_storage ub ehci_hcd usbcore And that's it. So if you suspect some module to be the culprit, it must be one of these. --=20 .''`. Martin Loschwitz Debian GNU/Linux developer : :' : madkiss@madkiss.org madkiss@debian.org `. `'` http://www.madkiss.org/ people.debian.org/~madkiss/ `- Use Debian GNU/Linux 3.0! See http://www.debian.org/ --4Ckj6UjgE2iN1+kY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFC8+tZHPo+jNcUXjARArdtAJ9VjyWKWkMarGCuK4oHqJJ7bkDipwCeIFTQ 2eDz3Nfo9QRdVm4xNlrot1g= =YnUw -----END PGP SIGNATURE----- --4Ckj6UjgE2iN1+kY--