USN-1256-1: Linux kernel (Natty backport) vulnerabilities

9 November 2011

Several security issues were fixed in the kernel.

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It was discovered that the /proc filesystem did not correctly handle
permission changes when programs executed. A local attacker could hold open
files to examine details about programs running with higher privileges,
potentially increasing the chances of exploiting additional
vulnerabilities. (CVE-2011-1020)

Vasiliy Kulikov discovered that the Bluetooth stack did not correctly clear
memory. A local attacker could exploit this to read kernel stack memory,
leading to a loss of privacy. (CVE-2011-1078)

Vasiliy Kulikov discovered that the Bluetooth stack did not correctly check
that device name strings were NULL terminated. A local attacker could
exploit this to crash the system, leading to a denial of service, or leak
contents of kernel stack memory, leading to a loss of privacy.
(CVE-2011-1079)

Vasiliy Kulikov discovered that bridge network filtering did not check that
name fields were NULL terminated. A local attacker could exploit this to
leak contents of kernel stack memory, leading to a loss of privacy.
(CVE-2011-1080)

Johan Hovold discovered that the DCCP network stack did not correctly
handle certain packet combinations. A remote attacker could send specially
crafted network traffic that would crash the system, leading to a denial of
service. (CVE-2011-1093)

Peter Huewe discovered that the TPM device did not correctly initialize
memory. A local attacker could exploit this to read kernel heap memory
contents, leading to a loss of privacy. (CVE-2011-1160)

Dan Rosenberg discovered that the IRDA subsystem did not correctly check
certain field sizes. If a system was using IRDA, a remote attacker could
send specially crafted traffic to crash the system or gain root privileges.
(CVE-2011-1180)

Ryan Sweat discovered that the GRO code did not correctly validate memory.
In some configurations on systems using VLANs, a remote attacker could send
specially crafted traffic to crash the system, leading to a denial of
service. (CVE-2011-1478)

It was discovered that the security fix for CVE-2010-4250 introduced a
regression. A remote attacker could exploit this to crash the system,
leading to a denial of service. (CVE-2011-1479)

Dan Rosenberg discovered that the X.25 Rose network stack did not correctly
handle certain fields. If a system was running with Rose enabled, a remote
attacker could send specially crafted traffic to gain root privileges.
(CVE-2011-1493)

It was discovered that the Stream Control Transmission Protocol (SCTP)
implementation incorrectly calculated lengths. If the net.sctp.addip_enable
variable was turned on, a remote attacker could send specially crafted
traffic to crash the system. (CVE-2011-1573)

Ryan Sweat discovered that the kernel incorrectly handled certain VLAN
packets. On some systems, a remote attacker could send specially crafted
traffic to crash the system, leading to a denial of service.
(CVE-2011-1576)

Timo Warns discovered that the GUID partition parsing routines did not
correctly validate certain structures. A local attacker with physical
access could plug in a specially crafted block device to crash the system,
leading to a denial of service. (CVE-2011-1577)

Phil Oester discovered that the network bonding system did not correctly
handle large queues. On some systems, a remote attacker could send
specially crafted traffic to crash the system, leading to a denial of
service. (CVE-2011-1581)

It was discovered that CIFS incorrectly handled authentication. When a user
had a CIFS share mounted that required authentication, a local user could
mount the same share without knowing the correct password. (CVE-2011-1585)

It was discovered that the GRE protocol incorrectly handled netns
initialization. A remote attacker could send a packet while the ip_gre
module was loading, and crash the system, leading to a denial of service.
(CVE-2011-1767)

It was discovered that the IP/IP protocol incorrectly handled netns
initialization. A remote attacker could send a packet while the ipip module
was loading, and crash the system, leading to a denial of service.
(CVE-2011-1768)

Ben Greear discovered that CIFS did not correctly handle direct I/O. A
local attacker with access to a CIFS partition could exploit this to crash
the system, leading to a denial of service. (CVE-2011-1771)

Timo Warns discovered that the EFI GUID partition table was not correctly
parsed. A physically local attacker that could insert mountable devices
could exploit this to crash the system or possibly gain root privileges.
(CVE-2011-1776)

Vasiliy Kulikov and Dan Rosenberg discovered that ecryptfs did not
correctly check the origin of mount points. A local attacker could exploit
this to trick the system into unmounting arbitrary mount points, leading to
a denial of service. (CVE-2011-1833)

Ben Hutchings reported a flaw in the kernel's handling of corrupt LDM
partitions. A local user could exploit this to cause a denial of service or
escalate privileges. (CVE-2011-2182)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not
correctly validate certain requests. A local attacker could exploit this to
consume CPU resources, leading to a denial of service. (CVE-2011-2213)

It was discovered that an mmap() call with the MAP_PRIVATE flag on
"/dev/zero" was incorrectly handled. A local attacker could exploit this to
crash the system, leading to a denial of service. (CVE-2011-2479)

Vasiliy Kulikov discovered that taskstats listeners were not correctly
handled. A local attacker could expoit this to exhaust memory and CPU
resources, leading to a denial of service. (CVE-2011-2484)

It was discovered that Bluetooth l2cap and rfcomm did not correctly
initialize structures. A local attacker could exploit this to read portions
of the kernel stack, leading to a loss of privacy. (CVE-2011-2492)

Sami Liedes discovered that ext4 did not correctly handle missing root
inodes. A local attacker could trigger the mount of a specially crafted
filesystem to cause the system to crash, leading to a denial of service.
(CVE-2011-2493)

Robert Swiecki discovered that mapping extensions were incorrectly handled.
A local attacker could exploit this to crash the system, leading to a
denial of service. (CVE-2011-2496)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled
certain L2CAP requests. If a system was using Bluetooth, a remote attacker
could send specially crafted traffic to crash the system or gain root
privileges. (CVE-2011-2497)

Ben Pfaff discovered that Classless Queuing Disciplines (qdiscs) were being
incorrectly handled. A local attacker could exploit this to crash the
system, leading to a denial of service. (CVE-2011-2525)

It was discovered that GFS2 did not correctly check block sizes. A local
attacker could exploit this to crash the system, leading to a denial of
service. (CVE-2011-2689)

It was discovered that the EXT4 filesystem contained multiple off-by-one
flaws. A local attacker could exploit this to crash the system, leading to
a denial of service. (CVE-2011-2695)

Fernando Gont discovered that the IPv6 stack used predictable fragment
identification numbers. A remote attacker could exploit this to exhaust
network resources, leading to a denial of service. (CVE-2011-2699)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not
correctly check the length of memory copies. If this hardware was
available, a local attacker could exploit this to crash the system or gain
root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when
Generic Receive Offload (CVE-2011-2723)

The performance counter subsystem did not correctly handle certain
counters. A local attacker could exploit this to crash the system, leading
to a denial of service. (CVE-2011-2918)

Time Warns discovered that long symlinks were incorrectly handled on Be
filesystems. A local attacker could exploit this with a malformed Be
filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Qianfeng Zhang discovered that the bridge networking interface incorrectly
handled certain network packets. A remote attacker could exploit this to
crash the system, leading to a denial of service. (CVE-2011-2942)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence
number generation. An attacker could use this flaw to possibly predict
sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain
large values. A remote attacker with a malicious server could exploit this
to crash the system or possibly execute arbitrary code as the root user.
(CVE-2011-3191)

Yasuaki Ishimatsu discovered a flaw in the kernel's clock implementation. A
local unprivileged attacker could exploit this causing a denial of service.
(CVE-2011-3209)

Yogesh Sharma discovered that CIFS did not correctly handle UNCs that had
no prefixpaths. A local attacker with access to a CIFS partition could
exploit this to crash the system, leading to a denial of service.
(CVE-2011-3363)

A flaw was discovered in the Linux kernel's AppArmor security interface
when invalid information was written to it. An unprivileged local user
could use this to cause a denial of service on the system. (CVE-2011-3619)

A flaw was found in the Linux kernel's /proc//map* interface. A local,
unprivileged user could exploit this flaw to cause a denial of service.
(CVE-2011-3637)

Scot Doyle discovered that the bridge networking interface incorrectly
handled certain network packets. A remote attacker could exploit this to
crash the system, leading to a denial of service. (CVE-2011-4087)

A bug was found in the way headroom check was performed in
udp6_ufo_fragment() function. A remote attacker could use this flaw to
crash the system. (CVE-2011-4326)

Ben Hutchings discovered several flaws in the Linux Rose (X.25 PLP) layer.
A local user or a remote user on an X.25 network could exploit these flaws
to execute arbitrary code as root. (CVE-2011-4914)

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Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 10.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed. If
you use linux-restricted-modules, you have to update that package as
well to get modules which work with the new kernel version. Unless you
manually uninstalled the standard kernel metapackages (e.g. linux-generic,
linux-server, linux-powerpc), a standard system upgrade will automatically
perform this as well.

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