USN-3160-1: Linux kernel vulnerabilities

20 December 2016

linux 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 - Linux kernel

Details

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 14.04 LTS
linux-image-3.13.0-106-generic - 3.13.0-106.153
linux-image-3.13.0-106-generic-lpae - 3.13.0-106.153
linux-image-3.13.0-106-lowlatency - 3.13.0-106.153
linux-image-3.13.0-106-powerpc-e500 - 3.13.0-106.153
linux-image-3.13.0-106-powerpc-e500mc - 3.13.0-106.153
linux-image-3.13.0-106-powerpc-smp - 3.13.0-106.153
linux-image-3.13.0-106-powerpc64-emb - 3.13.0-106.153
linux-image-3.13.0-106-powerpc64-smp - 3.13.0-106.153
linux-image-generic - 3.13.0.106.114
linux-image-generic-lpae - 3.13.0.106.114
linux-image-lowlatency - 3.13.0.106.114
linux-image-powerpc-e500 - 3.13.0.106.114
linux-image-powerpc-e500mc - 3.13.0.106.114
linux-image-powerpc-smp - 3.13.0.106.114
linux-image-powerpc64-emb - 3.13.0.106.114
linux-image-powerpc64-smp - 3.13.0.106.114

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