Several security issues were fixed in the kernel.
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)
6 March 2012
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
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)
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)
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.
Vulmon