SecurityTracker.com
    Home    |    View Topics    |    Search    |    Contact Us    |   

SecurityTracker
Archives


 


Category:   OS (UNIX)  >   NetBSD Vendors:   NetBSD
NetBSD modctl() Memory Allocation Error Lets Local Users Deny Service
SecurityTracker Alert ID:  1030766
SecurityTracker URL:  http://securitytracker.com/id/1030766
CVE Reference:   GENERIC-MAP-NOMATCH   (Links to External Site)
Date:  Aug 27 2014
Impact:   Denial of service via local system
Fix Available:  Yes  Vendor Confirmed:  Yes  
Version(s): 5.1 - 5.1.4, 5.2 - 5.2.2, 6.0 - 6.0.5, 6.1 - 6.1.4
Description:   A vulnerability was reported in NetBSD. A local user can cause denial of service conditions.

A local user can trigger an input validation flaw in the modctl() system call to cause a memory allocation error, leading to a system crash.

Maxime Villard reported this vulnerability.

Impact:   A local user can cause the target system to crash.
Solution:   The vendor has issued a fix.

The vendor's advisory is available at:

http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2014-011.txt.asc

Vendor URL:  ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2014-011.txt.asc (Links to External Site)
Cause:   Input validation error

Message History:   None.


 Source Message Contents

Subject:  NetBSD Security Advisory 2014-011: User-controlled memory allocation in the modctl system call

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

		NetBSD Security Advisory 2014-011
		=================================

Topic:		User-controlled memory allocation in the modctl system call


Version:	NetBSD-current:		source prior to Thu, Jul 10th 2014
		NetBSD 6.1 - 6.1.4:	affected
		NetBSD 6.0 - 6.0.5:	affected
		NetBSD 5.1 - 5.1.4:	affected
		NetBSD 5.2 - 5.2.2:	affected

Severity:	Local DoS

Fixed:		NetBSD-current:		Thu, Jul 10th 2014
		NetBSD-6-1 branch:	Mon, Jul 14th 2014
		NetBSD-6-0 branch:	Mon, Jul 14th 2014
		NetBSD-6 branch:	Mon, Jul 14th 2014
		NetBSD-5.2 branch:	Mon, Jul 14th 2014
		NetBSD-5.1 branch:	Mon, Jul 14th 2014
		NetBSD-5 branch:	Mon, Jul 14th 2014

Teeny versions released later than the fix date will contain the fix.

Please note that NetBSD releases prior to 5.1 are no longer supported.
It is recommended that all users upgrade to a supported release.


Abstract
========

Due to missing input validation checks, a local (un)privileged user
could cause the kernel to perform a zero-sized or unbounded memory
allocation, resulting in a crash.


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

The modctl system call takes as second argument a buffer which is
represented as a structure when loading a kernel module. This structure
indicates special information on how to load a module, including a
string pointer and the length of the string pointed to. A kernel buffer
of the same size is allocated, but no check was performed to ensure the
size is neither too low nor too high, thus allowing a local user to
crash the system.


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

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),               
  KERNCONF with the name of your kernel configuration file and  
  VERSION  with the file version below

File versions containing the fixes:

FILE  HEAD  netbsd-6  netbsd-6-1  netbsd-6-0  netbsd-5  netbsd-5-2  netbsd-5-1
- ----  ----  --------  ----------  ----------  --------  ----------  ----------
sys/kern/sys_module.c
      1.15  1.13.8.1  1.13.14.1   1.13.12.1   1.8.4.2   1.8.4.1.6.1 1.8.4.1.2.1

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

	# cd src
	# cvs update -d -P -r VERSION sys/kern/sys_module.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
=========

Thanks to Maxime Villard, who found the issue and provided a fix.


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

	2014-08-27	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 
  http://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2014-011.txt.asc

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


Copyright 2014, The NetBSD Foundation, Inc.  All Rights Reserved.
Redistribution permitted only in full, unmodified form.

$NetBSD: NetBSD-SA2014-011.txt,v 1.1 2014/08/27 00:33:51 tonnerre Exp $

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQIcBAEBAgAGBQJT/SeDAAoJEAZJc6xMSnBuBL4QAIW2I1UEwOmj5kWStYYl1Pxh
AZLvbbi2u89q1Dw2OHqycsCTA4E2FNMCJI0Dqr4jHYvTFjQY52K33vTw/u5K5YxC
etdYXa68W7u1rKedajx+H/BLBTKNHCwjL4uA7AsIs7XQTQqIYDKRr8SkPdH/j/kH
7Szd90WHWisDVzET+91sGbGmw7wFIiXm80Ovp+DI9/Aib13eQ9GlxEQ4cCRBBIwQ
Smu86UI92BYarbPjKq+INwbYSc0uZDnuUPXq2UgJtp10VpKDdxmYZPrn4nvggJOf
HCe95l9vo3L6Fs/5g5jU9TjiHd0X/SEfwSx0sN168U5+vyu2l87fCxSrFxM16aJW
N0b7PhrO6WOL3LPzZXXNDjUh2LxOINcNvB3zO8PAMrf4XOzYQfRhXByQlZ2orcOf
w6ly9sWBvSSgV39BkM8Lh+selVZ6z2mzlfL4nBa2Jb8CLTtiKfzPyDTmxIZcZuH5
SJ1P7nTFvwW5fk+8Ff7zo00gCikSa+vTfu29OdWgrdrwSyuIcP+ZO+gP7GHzcU5U
QQl1qzqx8PurKuMY732aigPyosPPb8KLRebokXWVUuygnd3MzJFpDsJhn/QiIXce
4YA7IYMBMGT6+5R0l57m950lCdnoBIf5pTu7Y3/jaAQBfTQHIGyhYItHSgwUe97N
gDnChdomglOFD4nWmOwp
=g8zM
-----END PGP SIGNATURE-----
 
 


Go to the Top of This SecurityTracker Archive Page





Home   |    View Topics   |    Search   |    Contact Us

This web site uses cookies for web analytics. Learn More

Copyright 2021, SecurityGlobal.net LLC