USN-3084-2: Linux kernel (Xenial HWE) vulnerabilities

19 September 2016

linux-lts-xenial 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-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

USN-3084-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 LTS.

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 versions:

Ubuntu 14.04 LTS
linux-image-4.4.0-38-generic - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-generic-lpae - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-lowlatency - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-powerpc-e500mc - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-powerpc-smp - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-powerpc64-emb - 4.4.0-38.57~14.04.1
linux-image-4.4.0-38-powerpc64-smp - 4.4.0-38.57~14.04.1

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.

References