1. Ubuntu Security Notices
  2. USN-1389-1

USN-1389-1: Linux kernel vulnerabilities

Publication date

6 March 2012

Overview

Several security issues were fixed in the kernel.

Releases

Packages

Details

Paolo Bonzini discovered a flaw in Linux’s handling of the SG_IO ioctl
command. A local user, or user in a VM could exploit this flaw to bypass
restrictions and gain read/write access to all data on the affected block
device. (CVE-2011-4127)

A flaw was found in KVM’s Programmable Interval Timer (PIT). When a virtual
interrupt control is not available a local user could use this to cause a
denial of service by starting a timer. (CVE-2011-4622)

A flaw was discovered in the XFS filesystem. If a local user mounts a
specially crafted XFS image it could potential execute arbitrary code on
the system. (CVE-2012-0038)

A flaw was found in the Linux kernel’s ext4 file system when mounting a
corrupt filesystem. A user-assisted remote attacker could exploit this flaw
to cause a denial of service. (

Paolo Bonzini discovered a flaw in Linux’s handling of the SG_IO ioctl
command. A local user, or user in a VM could exploit this flaw to bypass
restrictions and gain read/write access to all data on the affected block
device. (CVE-2011-4127)

A flaw was found in KVM’s Programmable Interval Timer (PIT). When a virtual
interrupt control is not available a local user could use this to cause a
denial of service by starting a timer. (CVE-2011-4622)

A flaw was discovered in the XFS filesystem. If a local user mounts a
specially crafted XFS image it could potential execute arbitrary code on
the system. (CVE-2012-0038)

A flaw was found in the Linux kernel’s ext4 file system when mounting a
corrupt filesystem. A user-assisted remote attacker could exploit this flaw
to cause a denial of service. (CVE-2012-2100)

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
10.04 lucid linux-image-2.6.32-39-lpia –  2.6.32-39.86
linux-image-2.6.32-39-generic-pae –  2.6.32-39.86
linux-image-2.6.32-39-sparc64 –  2.6.32-39.86
linux-image-2.6.32-39-ia64 –  2.6.32-39.86
linux-image-2.6.32-39-386 –  2.6.32-39.86
linux-image-2.6.32-39-powerpc –  2.6.32-39.86
linux-image-2.6.32-39-versatile –  2.6.32-39.86
linux-image-2.6.32-39-generic –  2.6.32-39.86
linux-image-2.6.32-39-powerpc64-smp –  2.6.32-39.86
linux-image-2.6.32-39-preempt –  2.6.32-39.86
linux-image-2.6.32-39-powerpc-smp –  2.6.32-39.86
linux-image-2.6.32-39-server –  2.6.32-39.86
linux-image-2.6.32-39-sparc64-smp –  2.6.32-39.86
linux-image-2.6.32-39-virtual –  2.6.32-39.86

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References

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