1. Ubuntu Security Notices
  2. USN-3160-2

USN-3160-2: Linux kernel (Trusty HWE) vulnerabilities

Publication date

20 December 2016

Overview

Several security issues were fixed in the kernel.

Releases

Packages

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)

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

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
12.04 precise linux-image-3.13.0-106-generic –  3.13.0-106.153~precise1
linux-image-generic-lpae-lts-trusty –  3.13.0.106.97
linux-image-3.13.0-106-generic-lpae –  3.13.0-106.153~precise1
linux-image-generic-lts-trusty –  3.13.0.106.97

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References

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