USN-3220-3: Linux kernel (AWS) vulnerability

Ubuntu Security Notice USN-3220-3

8th March, 2017

linux-aws 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-aws - Linux kernel for Amazon Web Services (AWS) systems

Details

USN-3220-1 fixed a vulnerability in the Linux kernel. This update
provides the corresponding updates for the Linux kernel for Amazon
Web Services (AWS).

Alexander Popov discovered that the N_HDLC line discipline implementation
in the Linux kernel contained a double-free vulnerability. A local attacker
could use this to cause a denial of service (system crash) or possibly gain
administrative privileges.

Update instructions

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

Ubuntu 16.04 LTS:
linux-image-4.4.0-1007-aws 4.4.0-1007.16
linux-image-aws 4.4.0.1007.8

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-2017-2636