USN-4301-1: Linux kernel vulnerabilities

25 March 2020

linux-aws-5.0, linux-gcp, linux-gke-5.0, linux-oracle-5.0, linux-azure vulnerabilities

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

  • Ubuntu 18.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux-aws-5.0 - 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-gke-5.0 - Linux kernel for Google Container Engine (GKE) systems
  • linux-oem-osp1 - Linux kernel for OEM processors
  • linux-oracle-5.0 - Linux kernel for Oracle Cloud systems

Details

It was discovered that the KVM implementation in the Linux kernel, when paravirtual TLB flushes are enabled in guests, the hypervisor in some situations could miss deferred TLB flushes or otherwise mishandle them. An attacker in a guest VM could use this to expose sensitive information (read memory from another guest VM). (CVE-2019-3016)

Paulo Bonzini discovered that the KVM hypervisor implementation in the Linux kernel could improperly let a nested (level 2) guest access the resources of a parent (level 1) guest in certain situations. An attacker could use this to expose sensitive information. (CVE-2020-2732)

It was discovered that the RPMSG character device interface in the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could possibly use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19053)

It was discovered that the Marvell Wi-Fi device driver in the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could use this to possibly cause a denial of service (kernel memory exhaustion). (CVE-2019-19056)

It was discovered that the Intel® Wi-Fi device driver in the Linux kernel device driver in the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could possibly use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19058, CVE-2019-19059)

It was discovered that the Brocade BFA Fibre Channel device driver in the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could possibly use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19066)

It was discovered that the Realtek RTL8xxx USB Wi-Fi device driver in the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could possibly use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19068)

Update instructions

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

Ubuntu 18.04 LTS
linux-image-5.0.0-1013-oracle - 5.0.0-1013.18
linux-image-5.0.0-1027-aws - 5.0.0-1027.30
linux-image-5.0.0-1032-gke - 5.0.0-1032.33
linux-image-5.0.0-1033-gcp - 5.0.0-1033.34
linux-image-5.0.0-1035-azure - 5.0.0-1035.37
linux-image-5.0.0-1043-oem-osp1 - 5.0.0-1043.48
linux-image-aws-edge - 5.0.0.1027.41
linux-image-azure - 5.0.0.1035.46
linux-image-gcp - 5.0.0.1033.37
linux-image-gke-5.0 - 5.0.0.1032.20
linux-image-oem-osp1 - 5.0.0.1043.48
linux-image-oracle - 5.0.0.1013.13

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