4.7 - USN-3160-2

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

- Ubuntu 12.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description: - linux-lts-trusty: Linux hardware enablement kernel from Trusty for Precise

Details:

USN-3160-1 fixed vulnerabilities in the Linux kernel for Ubuntu 14.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 14.04 LTS for Ubuntu 12.04 LTS.

CAI Qian discovered that shared bind mounts in a mount namespace exponentially added entries without restriction to the Linux kernel's mount table. A local attacker could use this to cause a denial of service (system crash). (CVE-2016-6213)

It was discovered that a race condition existed in the procfs environ_read function in the Linux kernel, leading to an integer underflow. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2016-7916)

Update instructions:

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

Ubuntu 12.04 LTS:
linux-image-3.13.0-106-generic 3.13.0-106.153~precise1
linux-image-3.13.0-106-generic-lpae 3.13.0-106.153~precise1
linux-image-generic-lpae-lts-trusty 3.13.0.106.97
linux-image-generic-lts-trusty 3.13.0.106.97

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-3160-2
http://www.ubuntu.com/usn/usn-3160-1
CVE-2016-6213, CVE-2016-7916

Package Information:
https://launchpad.net/ubuntu/+source/linux-lts-trusty/3.13.0-106.153~precise1