-----BEGIN PGP SIGNED MESSAGE-----
AUSCERT External Security Bulletin Redistribution
ESB-2006.0870 -- [NetBSD]
Multiple denial of service issues
28 November 2006
AusCERT Security Bulletin Summary
Operating System: NetBSD
Impact: Denial of Service
Access: Existing Account
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
NetBSD Security Advisory 2006-026
Topic: Multiple denial of service issues
Version: NetBSD-current: source prior to October 23, 2006
NetBSD 3.1: not affected
NetBSD 3.0.2: not affected
NetBSD 3.0.1: affected
NetBSD 3.0: affected
NetBSD 2.1: affected
NetBSD 2.0.*: affected
NetBSD 2.0: affected
Severity: Denial of service issues ranging from resource leaks to
Fixed: NetBSD-current: October 23, 2006
NetBSD-3-0 branch: October 24, 2006
NetBSD-3 branch: October 24, 2006
NetBSD-2-1 branch: October 29, 2006
NetBSD-2-0 branch: October 29, 2006
NetBSD-2 branch: October 29, 2006
There are multiple denial of service issues that can result in resource
leaks or kernel panics.
* Dangling socket could exhaust local system resources
If a user supplies a bad 'name' or 'namelen' parameter to accept(2) this
could leave a dangling socket. If bad parameters were supplied and a
copyout(9) failed, the 'file' structure was cleaned up, but not the
associated socket. This could leave sockets in the CLOSE_WAIT state that
could never be closed.
* sendmsg(2) panic
On 64-bit architectures (e.g. amd64, sparc64, and alpha) sendmsg(2)
can cause a kernel panic, due to insufficient checks of the 'msg_controllen'
parameter in sendit().
* mount_procfs panic (with -o linux)
Trying to read '/emul/linux/proc/0/stat' on a procfs mounted with the 'linux'
option results in a kernel panic. The process in question has to no parent
process, resulting in a NULL dereference due to insufficient checks.
Solutions and Workarounds
* The sendmsg(2) panic only affects 64-bit systems.
* By default, procfs is not mounted with the 'linux' option, however it is
often enabled when using Linux emulation.
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 sys/kern/uipc_syscalls.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:
The dangling socket issue was discovered and fixed by Sean Boudreau.
The sendmsg(2) panic was discovered and reported by Ryo Shimizu.
The mount_procfs panic was discovered and reported Nicolas Joly.
2006-11-27 Initial release
Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at
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-SA2006-026.txt,v 1.3 2006/11/27 20:14:45 adrianp Exp $
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (NetBSD)
- -----END PGP SIGNATURE-----
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to email@example.com
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
Australian Computer Emergency Response Team
The University of Queensland
Internet Email: firstname.lastname@example.org
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
-----BEGIN PGP SIGNATURE-----
-----END PGP SIGNATURE-----