USN-4069-1: Linux kernel vulnerabilities

23 July 2019

linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities

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

  • Ubuntu 19.04

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • 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-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

It was discovered that an integer overflow existed in the Linux kernel when reference counting pages, leading to potential use-after-free issues. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11487)

Jann Horn discovered that a race condition existed in the Linux kernel when performing core dumps. A local attacker could use this to cause a denial of service (system crash) or expose sensitive information. (CVE-2019-11599)

It was discovered that the ext4 file system implementation in the Linux kernel did not properly zero out memory in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2019-11833)

It was discovered that the Bluetooth Human Interface Device Protocol (HIDP) implementation in the Linux kernel did not properly verify strings were NULL terminated in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2019-11884)

Update instructions

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

Ubuntu 19.04
linux-image-5.0.0-1011-aws - 5.0.0-1011.12
linux-image-5.0.0-1011-gcp - 5.0.0-1011.11
linux-image-5.0.0-1011-kvm - 5.0.0-1011.12
linux-image-5.0.0-1012-azure - 5.0.0-1012.12
linux-image-5.0.0-1013-raspi2 - 5.0.0-1013.13
linux-image-5.0.0-1017-snapdragon - 5.0.0-1017.18
linux-image-5.0.0-21-generic - 5.0.0-21.22
linux-image-5.0.0-21-generic-lpae - 5.0.0-21.22
linux-image-5.0.0-21-lowlatency - 5.0.0-21.22
linux-image-aws - 5.0.0.1011.11
linux-image-azure - 5.0.0.1012.11
linux-image-gcp - 5.0.0.1011.11
linux-image-generic - 5.0.0.21.22
linux-image-generic-lpae - 5.0.0.21.22
linux-image-gke - 5.0.0.1011.11
linux-image-kvm - 5.0.0.1011.11
linux-image-lowlatency - 5.0.0.21.22
linux-image-raspi2 - 5.0.0.1013.10
linux-image-snapdragon - 5.0.0.1017.10
linux-image-virtual - 5.0.0.21.22

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