bugtraq - NetBSD Security Advisory 2006-001: Kernfs kernel memory disclosure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <23927.1136822005@gendalia.org>
Date: Mon, 09 Jan 2006 09:53:25 -0600
From: NetBSD Security Officer <security-officer@...BSD.org>
To: bugtraq@...urityfocus.com
Subject: NetBSD Security Advisory 2006-001: Kernfs kernel memory disclosure

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

		 NetBSD Security Advisory 2006-001
		 =================================

Topic:		Kernfs kernel memory disclosure

Version:	NetBSD-current:	source prior to November 23, 2005
		NetBSD 3.0:	not affected
		NetBSD 2.1:	affected
		NetBSD 2.0.3:	affected
		NetBSD 2.0:	affected
		NetBSD 1.6:	affected

Severity:	kernel sensitive information can be disclosed

Fixed:		NetBSD-current:		November 23, 2005
		NetBSD-3   branch:	November 24, 2005
		NetBSD-2.1 branch:	November 29, 2005
		NetBSD-2.0 branch:	November 29, 2005
		NetBSD-2   branch:	November 29, 2005
		NetBSD-1.6 branch:	November 29, 2005

Abstract
========

The kernfs filesystem does not validate file offsets properly and
a userlevel non-privileged process can read arbitrary kernel memory
locations.

Technical Details
=================

The lseek(2) system call for the kernfs file system has insufficient
bounds checking, allowing arbitrary memory locations to be read.

Solutions and Workarounds
=========================

A workaround for the issue is to not mount the kernfs file system.

For all NetBSD versions, you need to obtain fixed kernel sources,
rebuild and install the new kernel, and reboot the system.

The fixed source may be obtained from the NetBSD CVS repository.

The following instructions briefly summarise how to upgrade your
kernel.  In these instructions, replace:

  ARCH     with your architecture (from uname -m), and 
  KERNCONF with the name of your kernel configuration file.

To update from CVS, re-build, and re-install the kernel:

        # cd src
        # cvs update -d -P sys/miscfs/kernfs/kernfs_vnops.c
	# ./build.sh kernel=KERNCONF
	# mv /netbsd /netbsd.old
	# cp sys/arch/ARCH/compile/obj/KERNCONF/netbsd /netbsd
	# shutdown -r now

For more information on how to do this, see:

   http://www.NetBSD.org/guide/en/chap-kernel.html

Thanks To
=========

Ejovi Nuwere from SecurityLab for reporting the bug and Christos Zoulas
for the fix.

Revision History
================

	2006-01-09	Initial release

More Information
================

Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at 
  ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2006-001.txt.asc

Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.org/ and http://www.NetBSD.org/Security/.

Copyright 2006, The NetBSD Foundation, Inc.  All Rights Reserved.
Redistribution permitted only in full, unmodified form.

$NetBSD: NetBSD-SA2006-001.txt,v 1.5 2006/01/09 14:48:35 gendalia Exp $

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (NetBSD)

iQCVAwUBQ8J3+z5Ru2/4N2IFAQIizAP/V8ad1aW7fMvDFdymQveBoW0U+7+tJgoV
lzIbV7gt8tkDw0jANVqvorLoy0bC09YxnsvG/MmEwjvt6OHl80i1xd4idWhBIwSc
3NsjNd0RKiaf1Xj8pGDiuiJI8+c/2+LMhdtuXKPu7WM4EMVj7NHmxxZlzH6bFJTI
eEunu2Me4ms=
=Z6b1
-----END PGP SIGNATURE-----