USN-3251-2: Linux kernel (HWE) vulnerability

Ubuntu Security Notice USN-3251-2

29th March, 2017

linux-hwe vulnerability

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

  • Ubuntu 16.04 LTS

Summary

The system could be made to crash or run programs as an administrator.

Software description

  • linux-hwe - Linux hardware enablement (HWE) kernel

Details

USN-3251-1 fixed a vulnerability in the Linux kernel for Ubuntu 16.10.
This update provides the corresponding updates for the Linux Hardware
Enablement (HWE) kernel from Ubuntu 16.10 for Ubuntu 16.04 LTS.

It was discovered that the xfrm framework for transforming packets in the
Linux kernel did not properly validate data received from user space. A
local attacker could use this to cause a denial of service (system crash)
or execute arbitrary code with administrative privileges.

Update instructions

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

Ubuntu 16.04 LTS:
linux-image-4.8.0-45-generic-lpae 4.8.0-45.48~16.04.1
linux-image-lowlatency-hwe-16.04 4.8.0.45.17
linux-image-4.8.0-45-generic 4.8.0-45.48~16.04.1
linux-image-generic-hwe-16.04 4.8.0.45.17
linux-image-4.8.0-45-lowlatency 4.8.0-45.48~16.04.1
linux-image-generic-lpae-hwe-16.04 4.8.0.45.17

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

CVE-2017-7184