1. Ubuntu Security Notices
  2. USN-1285-1

USN-1285-1: Linux kernel vulnerabilities

Publication date

29 November 2011

Overview

Several security issues were fixed in the kernel.

Releases

Packages

Details

Andrea Righi discovered a race condition in the KSM memory merging support.
If KSM was being used, a local attacker could exploit this to crash the
system, leading to a denial of service. (CVE-2011-2183)

Vasily Averin discovered that the NFS Lock Manager (NLM) incorrectly
handled unlock requests. A local attacker could exploit this to cause a
denial of service. (CVE-2011-2491)

Vasiliy Kulikov discovered that taskstats did not enforce access
restrictions. A local attacker could exploit this to read certain
information, leading to a loss of privacy. (CVE-2011-2494)

Vasiliy Kulikov discovered that /proc/PID/io did not enforce access
restrictions. A local attacker could exploit this to read certain
information, leading to a loss of privacy. (CVE-2011-2495)

It was discovered...

Andrea Righi discovered a race condition in the KSM memory merging support.
If KSM was being used, a local attacker could exploit this to crash the
system, leading to a denial of service. (CVE-2011-2183)

Vasily Averin discovered that the NFS Lock Manager (NLM) incorrectly
handled unlock requests. A local attacker could exploit this to cause a
denial of service. (CVE-2011-2491)

Vasiliy Kulikov discovered that taskstats did not enforce access
restrictions. A local attacker could exploit this to read certain
information, leading to a loss of privacy. (CVE-2011-2494)

Vasiliy Kulikov discovered that /proc/PID/io did not enforce access
restrictions. A local attacker could exploit this to read certain
information, leading to a loss of privacy. (CVE-2011-2495)

It was discovered that the wireless stack incorrectly verified SSID
lengths. A local attacker could exploit this to cause a denial of service
or gain root privileges. (CVE-2011-2517)

Christian Ohm discovered that the perf command looks for configuration
files in the current directory. If a privileged user were tricked into
running perf in a directory containing a malicious configuration file, an
attacker could run arbitrary commands and possibly gain privileges.
(CVE-2011-2905)

Vasiliy Kulikov discovered that the Comedi driver did not correctly clear
memory. A local attacker could exploit this to read kernel stack memory,
leading to a loss of privacy. (CVE-2011-2909)

Update instructions

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

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
11.04 natty linux-image-2.6.38-13-powerpc –  2.6.38-13.52
linux-image-2.6.38-13-powerpc64-smp –  2.6.38-13.52
linux-image-2.6.38-13-generic-pae –  2.6.38-13.52
linux-image-2.6.38-13-versatile –  2.6.38-13.52
linux-image-2.6.38-13-generic –  2.6.38-13.52
linux-image-2.6.38-13-virtual –  2.6.38-13.52
linux-image-2.6.38-13-server –  2.6.38-13.52
linux-image-2.6.38-13-omap –  2.6.38-13.52
linux-image-2.6.38-13-powerpc-smp –  2.6.38-13.52

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References

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