USN-1363-1: Linux kernel vulnerabilities

13 February 2012

linux vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 11.10


Several security issues were fixed in the kernel.

Software Description

  • linux - Linux kernel


A bug was discovered in the Linux kernel’s calculation of OOM (Out of memory) scores, that would result in the wrong process being killed. A user could use this to kill the process with the highest OOM score, even if that process belongs to another user or the system. (CVE-2011-4097)

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)

Andy Whitcroft discovered a that the Overlayfs filesystem was not doing the extended permission checks needed by cgroups and Linux Security Modules (LSMs). A local user could exploit this to by-pass security policy and access files that should not be accessible. (CVE-2012-0055)

A flaw was found in the linux kernels IPv4 IGMP query processing. A remote attacker could exploit this to cause a denial of service. (CVE-2012-0207)

Update instructions

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

Ubuntu 11.10
linux-image-3.0.0-16-generic - 3.0.0-16.28
linux-image-3.0.0-16-generic-pae - 3.0.0-16.28
linux-image-3.0.0-16-omap - 3.0.0-16.28
linux-image-3.0.0-16-powerpc - 3.0.0-16.28
linux-image-3.0.0-16-powerpc-smp - 3.0.0-16.28
linux-image-3.0.0-16-powerpc64-smp - 3.0.0-16.28
linux-image-3.0.0-16-server - 3.0.0-16.28
linux-image-3.0.0-16-virtual - 3.0.0-16.28

To update your system, please follow these instructions:

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.