USN-4041-2: Linux kernel (HWE) update

29 June 2019

linux-lts-xenial, linux-aws, linux-azure update

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

  • Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

USN-4041-1 provided updates for the Linux kernel in Ubuntu. This update provides the corresponding updates for the Linux kernel for Ubuntu 16.04 ESM.

USN-4017-2 fixed vulnerabilities in the Linux kernel. Unfortunately, the update introduced a regression that interfered with networking applications that setup very low SO_SNDBUF values. This update fixes the problem.

We apologize for the inconvenience.

Jonathan Looney discovered that the Linux kernel could be coerced into segmenting responses into multiple TCP segments. A remote attacker could construct an ongoing sequence of requests to cause a denial of service. (CVE-2019-11479)

Update instructions

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

Ubuntu 14.04 ESM
linux-image-4.15.0-1049-azure - 4.15.0-1049.54~14.04.1
linux-image-4.4.0-1048-aws - 4.4.0-1048.52
linux-image-4.4.0-154-generic - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-generic-lpae - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-lowlatency - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-powerpc-e500mc - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-powerpc-smp - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-powerpc64-emb - 4.4.0-154.181~14.04.1
linux-image-4.4.0-154-powerpc64-smp - 4.4.0-154.181~14.04.1
linux-image-aws - 4.4.0.1048.49
linux-image-azure - 4.15.0.1049.36
linux-image-generic-lpae-lts-xenial - 4.4.0.154.135
linux-image-generic-lts-xenial - 4.4.0.154.135
linux-image-lowlatency-lts-xenial - 4.4.0.154.135
linux-image-powerpc-e500mc-lts-xenial - 4.4.0.154.135
linux-image-powerpc-smp-lts-xenial - 4.4.0.154.135
linux-image-powerpc64-emb-lts-xenial - 4.4.0.154.135
linux-image-powerpc64-smp-lts-xenial - 4.4.0.154.135
linux-image-virtual-lts-xenial - 4.4.0.154.135

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