NetBSD Security Advisory 2014-012: Memory leak in the setsockopt system call

[NetBSD Security Officer <security-officer%NetBSD.org@localhost>]

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                NetBSD Security Advisory 2014-012
                =================================

Topic:          Memory leak in the setsockopt system call


Version:        NetBSD-current:         source prior to Sat, Aug 16th 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:         Sat, Aug 16th 2014
                NetBSD-7 branch:        Sun, Aug 24th 2014
                NetBSD-6-0 branch:      Wed, Aug 27th 2014
                NetBSD-6-1 branch:      Wed, Aug 27th 2014
                NetBSD-6 branch:        Wed, Aug 27th 2014
                NetBSD-5.2 branch:      Wed, Aug 27th 2014
                NetBSD-5.1 branch:      Wed, Aug 27th 2014
                NetBSD-5 branch:        Wed, Aug 27th 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
========

A memory leak in the kernel could allow a local user to use up kernel
memory via repeated calls to the setsockopt system call, and thus to
freeze - or eventually panic - the system.


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

When calling the setsockopt system call on an ipv6 socket with specific
arguments, a kernel buffer allocated to temporarily hold the socket
option data was not freed. Performing such a call in a loop would cause
the kernel to run out of memory and eventually panic.


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-7  netbsd-6  netbsd-6-1  netbsd-6-0
 ----  ----   --------  --------  ----------  ----------
 sys/netinet6/ip6_output.c
       1.158  1.157.2.1 1.145.2.1 1.145.8.1   1.145.6.1

 FILE  netbsd-5     netbsd-5-2     netbsd-5-1
 ----  --------     ----------     ----------
 sys/netinet6/ip6_output.c
       1.135.2.2    1.135.2.1.10.1 1.135.2.1.6.1

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

        # cd src
        # cvs update -d -P -r VERSION sys/netinet6/ip6_output.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 for developing a code scanner which detected
the issue, and Ryota Ozaki for helping in developing a fix.


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

        2014-09-08      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-SA2014-012.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-SA2014-012.txt,v 1.1 2014/09/08 21:18:53 tonnerre Exp $

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