USN-4041-1: Linux kernel update

29 June 2019

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-4.15 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oem - Linux kernel for OEM processors
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

USN-4017-1 fixed vulnerabilities in the Linux kernel for Ubuntu.
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.

Update instructions

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

Ubuntu 19.04
Ubuntu 18.10
Ubuntu 18.04
Ubuntu 16.04

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.

Related notices

  • USN-4041-2: linux-image-powerpc64-emb-lts-xenial, linux-image-4.4.0-154-generic, linux-azure, linux-image-4.4.0-154-powerpc-e500mc, linux-image-aws, linux-image-generic-lts-xenial, linux-image-lowlatency-lts-xenial, linux-image-4.15.0-1049-azure, linux-image-4.4.0-1048-aws, linux-image-virtual-lts-xenial, linux-lts-xenial, linux-image-4.4.0-154-lowlatency, linux-aws, linux-image-4.4.0-154-generic-lpae, linux-image-generic-lpae-lts-xenial, linux-image-powerpc64-smp-lts-xenial, linux-image-azure, linux-image-4.4.0-154-powerpc64-smp, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-4.4.0-154-powerpc-smp, linux-image-4.4.0-154-powerpc64-emb