USN-2802-1: Linux kernel vulnerability

10 November 2015

The system could be made to crash under certain conditions.



  • linux - Linux kernel


Ben Serebrin discovered that the KVM hypervisor implementation in the Linux
kernel did not properly catch Alignment Check exceptions. An attacker in a
guest virtual machine could use this to cause a denial of service (system
crash) in the host OS.

Update instructions

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

Ubuntu 15.04

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.