Several security issues were fixed in the kernel.
A flaw was discovered in the Linux kernel’s KVM (kernel virtual machine). An administrative user in the guest OS could leverage this flaw to cause a denial of service in the host OS. (CVE-2012-2121)
21 September 2012
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the kernel.
A flaw was discovered in the Linux kernel’s KVM (kernel virtual machine). An administrative user in the guest OS could leverage this flaw to cause a denial of service in the host OS. (CVE-2012-2121)
Ben Hutchings reported a flaw in the Linux kernel with some network drivers that support TSO (TCP segment offload). A local or peer user could exploit this flaw to to cause a denial of service. (CVE-2012-3412)
Jay Fenlason and Doug Ledford discovered a bug in the Linux kernel implementation of RDS sockets. A local unprivileged user could potentially use this flaw to read privileged information from the kernel. (CVE-2012-3430)
A flaw was discovered in the madvise feature of the Linux kernel’s memory subsystem. An unprivileged local use could exploit the flaw to cause a denial of service (crash the system). (CVE-2012-3511)
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.