USN-3508-2: Linux kernel (HWE) vulnerabilities

Ubuntu Security Notice USN-3508-2

7th December, 2017

linux-hwe vulnerabilities

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

  • Ubuntu 16.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software description

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

Details

USN-3508-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04.
This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 17.04 for Ubuntu
16.04 LTS.

Mohamed Ghannam discovered that a use-after-free vulnerability existed in
the Netlink subsystem (XFRM) in the Linux kernel. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-16939)

It was discovered that the Linux kernel did not properly handle copy-on-
write of transparent huge pages. A local attacker could use this to cause a
denial of service (application crashes) or possibly gain administrative
privileges. (CVE-2017-1000405)

Yonggang Guo discovered that a race condition existed in the driver
subsystem in the Linux kernel. A local attacker could use this to possibly
gain administrative privileges. (CVE-2017-12146)

Update instructions

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

Ubuntu 16.04 LTS:
linux-image-4.10.0-42-generic-lpae 4.10.0-42.46~16.04.1
linux-image-4.10.0-42-generic 4.10.0-42.46~16.04.1
linux-image-generic-hwe-16.04 4.10.0.42.44
linux-image-lowlatency-hwe-16.04 4.10.0.42.44
linux-image-4.10.0-42-lowlatency 4.10.0-42.46~16.04.1
linux-image-generic-lpae-hwe-16.04 4.10.0.42.44

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-2017-1000405, CVE-2017-12146, CVE-2017-16939