USN-3084-3: Linux kernel (Raspberry Pi 2) vulnerabilities

Ubuntu Security Notice USN-3084-3

19th September, 2016

linux-raspi2 vulnerabilities

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

Ubuntu 16.04 LTS

Summary

Several security issues were fixed in the kernel.

Software description

linux-raspi2
– Linux kernel for Raspberry Pi 2

Details

Pengfei Wang discovered a race condition in the audit subsystem in the
Linux kernel. A local attacker could use this to corrupt audit logs or
disrupt system-call auditing. (CVE-2016-6136)

It was discovered that the powerpc and powerpc64 hypervisor-mode KVM
implementation in the Linux kernel for did not properly maintain state
about transactional memory. An unprivileged attacker in a guest could cause
a denial of service (CPU lockup) in the host OS. (CVE-2016-5412)

Pengfei Wang discovered a race condition in the Chrome OS embedded
controller device driver in the Linux kernel. A local attacker could use
this to cause a denial of service (system crash). (CVE-2016-6156)

Update instructions

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

Ubuntu 16.04 LTS:: linux-image-4.4.0-1023-raspi2

4.4.0-1023.29

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.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.