4.6 - USN-3084-1

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: Linux kernel

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 versions:

Ubuntu 16.04 LTS:
linux-image-4.4.0-38-generic 4.4.0-38.57
linux-image-4.4.0-38-generic-lpae 4.4.0-38.57
linux-image-4.4.0-38-lowlatency 4.4.0-38.57
linux-image-4.4.0-38-powerpc-e500mc 4.4.0-38.57
linux-image-4.4.0-38-powerpc-smp 4.4.0-38.57
linux-image-4.4.0-38-powerpc64-emb 4.4.0-38.57
linux-image-4.4.0-38-powerpc64-smp 4.4.0-38.57

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:
http://www.ubuntu.com/usn/usn-3084-1
CVE-2016-5412, CVE-2016-6136, CVE-2016-6156

Package Information:
https://launchpad.net/ubuntu/+source/linux/4.4.0-38.57