USN-1384-1: Linux kernel (Oneiric backport) vulnerabilities

Ubuntu Security Notice USN-1384-1

6th March, 2012

linux-lts-backport-oneiric vulnerabilities

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

  • Ubuntu 10.04 LTS

Summary

Several security issues were fixed in the kernel.

Software description

  • linux-lts-backport-oneiric - Linux kernel backport from Oneiric

Details


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)

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)

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)

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

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

Ubuntu 10.04 LTS:
linux-image-3.0.0-16-virtual 3.0.0-16.29~lucid1
linux-image-3.0.0-16-generic 3.0.0-16.29~lucid1
linux-image-3.0.0-16-server 3.0.0-16.29~lucid1
linux-image-3.0.0-16-generic-pae 3.0.0-16.29~lucid1

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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.

References

CVE-2011-4097, CVE-2011-4127, CVE-2011-4622, CVE-2012-0038, CVE-2012-0055, CVE-2012-0207, CVE-2012-2100