============================================================================
Ubuntu Security Notice USN-2589-1
April 30, 2015

linux-lts-utopic vulnerabilities
============================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux-lts-utopic: Linux hardware enablement kernel from Utopic

Details:

Jan Beulich discovered the Xen virtual machine subsystem of the Linux
kernel did not properly restrict access to PCI command registers. A local
guest user could exploit this flaw to cause a denial of service (host
crash). (CVE-2015-2150)

A stack overflow was discovered in the the microcode loader for the intel
x86 platform. A local attacker could exploit this flaw to cause a denial of
service (kernel crash) or to potentially execute code with kernel
privileges. (CVE-2015-2666)

A privilege escalation was discovered in the fork syscal vi the int80 entry
on 64 bit kernels with 32 bit emulation support. An unprivileged local
attacker could exploit this flaw to increase their privileges on the
system. (CVE-2015-2830)

It was discovered that the Linux kernel's IPv6 networking stack has a flaw
that allows using route advertisement (RA) messages to set the 'hop_limit'
to values that are too low. An unprivileged attacker on a local network
could exploit this flaw to cause a denial of service (IPv6 messages
dropped). (CVE-2015-2922)

Update instructions:

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

Ubuntu 14.04 LTS:
  linux-image-3.16.0-36-generic   3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-generic-lpae  3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-lowlatency  3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-powerpc-e500mc  3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-powerpc-smp  3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-powerpc64-emb  3.16.0-36.48~14.04.1
  linux-image-3.16.0-36-powerpc64-smp  3.16.0-36.48~14.04.1

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.

References:
  https://www.ubuntu.com/usn/usn-2589-1
  CVE-2015-2150, CVE-2015-2666, CVE-2015-2830, CVE-2015-2922

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-utopic/3.16.0-36.48~14.04.1