Ubuntu Update for linux USN-1720-1

Solution
Please Install the Updated Packages.
Insight
It was discovered that hypervkvpd, which is distributed in the Linux kernel, was not correctly validating the origin on Netlink messages. An untrusted local user can cause a denial of service of Linux guests in Hyper-V virtualization environments. (CVE-2012-2669) Dmitry Monakhov reported a race condition flaw the Linux ext4 filesystem that can expose stale data. An unprivileged user could exploit this flaw to cause an information leak. (CVE-2012-4508) Florian Weimer discovered that hypervkvpd, which is distributed in the Linux kernel, was not correctly validating source addresses of netlink packets. An untrusted local user can cause a denial of service by causing hypervkvpd to exit. (CVE-2012-5532) Andrew Cooper of Citrix reported a Xen stack corruption in the Linux kernel. An unprivileged user in a 32bit PVOPS guest can cause the guest kernel to crash, or operate erroneously. (CVE-2013-0190)
Affected
linux on Ubuntu 11.10