1. Ubuntu Security Notices
  2. USN-2846-1

USN-2846-1: Linux kernel vulnerabilities

Publication date

19 December 2015

Overview

Several security issues were fixed in the kernel.

Releases

Packages

Details

Felix Wilhelm discovered a race condition in the Xen paravirtualized
drivers which can cause double fetch vulnerabilities. An attacker in the
paravirtualized guest could exploit this flaw to cause a denial of service
(crash the host) or potentially execute arbitrary code on the host.
(CVE-2015-8550)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform consistency checks on the device’s state. An attacker could exploit this
flaw to cause a denial of service (NULL dereference) on the host.
(CVE-2015-8551)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform consistency checks on the device’s state. An attacker could exploit this
flaw to cause a denial of service by flooding the logging system with
WARN() messages causing the initial domain to exhaust disk space.
(

Felix Wilhelm discovered a race condition in the Xen paravirtualized
drivers which can cause double fetch vulnerabilities. An attacker in the
paravirtualized guest could exploit this flaw to cause a denial of service
(crash the host) or potentially execute arbitrary code on the host.
(CVE-2015-8550)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform consistency checks on the device’s state. An attacker could exploit this
flaw to cause a denial of service (NULL dereference) on the host.
(CVE-2015-8551)

Konrad Rzeszutek Wilk discovered the Xen PCI backend driver does not
perform consistency checks on the device’s state. An attacker could exploit this
flaw to cause a denial of service by flooding the logging system with
WARN() messages causing the initial domain to exhaust disk space.
(CVE-2015-8552)

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. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, 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
12.04 precise linux-image-3.2.0-97-generic –  3.2.0-97.137
linux-image-3.2.0-97-generic-pae –  3.2.0-97.137
linux-image-3.2.0-97-highbank –  3.2.0-97.137
linux-image-3.2.0-97-omap –  3.2.0-97.137
linux-image-3.2.0-97-powerpc-smp –  3.2.0-97.137
linux-image-3.2.0-97-powerpc64-smp –  3.2.0-97.137
linux-image-3.2.0-97-virtual –  3.2.0-97.137

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References

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