1. Ubuntu Security Notices
  2. USN-3732-1

USN-3732-1: Linux kernel vulnerability

Publication date

6 August 2018

Overview

The system could be made unavailable if it received specially crafted network traffic.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-oem - Linux kernel for OEM processors
  • linux-raspi2 - Linux kernel for Raspberry Pi 2

Details

Juha-Matti Tilli discovered that the TCP implementation in the Linux kernel
performed algorithmically expensive operations in some situations when
handling incoming packets. A remote attacker could use this to cause a
denial of service.

Juha-Matti Tilli discovered that the TCP implementation in the Linux kernel
performed algorithmically expensive operations in some situations when
handling incoming packets. A remote attacker could use this to cause a
denial of service.

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
18.04 bionic linux-image-4.15.0-1015-gcp –  4.15.0-1015.15
linux-image-4.15.0-1017-aws –  4.15.0-1017.17
linux-image-4.15.0-1017-kvm –  4.15.0-1017.17
linux-image-4.15.0-1018-raspi2 –  4.15.0-1018.19
linux-image-4.15.0-30-generic –  4.15.0-30.32
linux-image-4.15.0-30-generic-lpae –  4.15.0-30.32
linux-image-4.15.0-30-lowlatency –  4.15.0-30.32
linux-image-4.15.0-30-snapdragon –  4.15.0-30.32

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References

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