Several security issues were fixed in the kernel.
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)
12 February 2013
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
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)
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)
The problem can be corrected by updating your system to the following package versions:
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.
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