1. Ubuntu Security Notices
  2. USN-4363-1

USN-4363-1: Linux kernel vulnerabilities

Publication date

28 May 2020

Overview

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-azure-4.15 - 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 systems
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi (V7) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

It was discovered that the Serial CAN interface driver in the Linux kernel
did not properly initialize data. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-11494)

It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)

David Gibson discovered that the Linux kernel on Power9 CPUs did not
properly save and restore Authority Mask registers state in some
situations. A local attacker in a guest VM could use this to cause a denial
of service (host system crash). (CVE-2020-11669)

It was discovered that the block layer in the Linux kernel contained a race
condition...

It was discovered that the Serial CAN interface driver in the Linux kernel
did not properly initialize data. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-11494)

It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)

David Gibson discovered that the Linux kernel on Power9 CPUs did not
properly save and restore Authority Mask registers state in some
situations. A local attacker in a guest VM could use this to cause a denial
of service (host system crash). (CVE-2020-11669)

It was discovered that the block layer in the Linux kernel contained a race
condition leading to a use-after-free vulnerability. A local attacker could
possibly use this to cause a denial of service (system crash) or execute
arbitrary code. (CVE-2020-12657)

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-4.15.0-101-generic –  4.15.0-101.102
linux-image-4.15.0-101-generic-lpae –  4.15.0-101.102
linux-image-4.15.0-101-lowlatency –  4.15.0-101.102
linux-image-4.15.0-1039-oracle –  4.15.0-1039.43
linux-image-4.15.0-1059-gke –  4.15.0-1059.62
linux-image-4.15.0-1060-kvm –  4.15.0-1060.61
linux-image-4.15.0-1062-raspi2 –  4.15.0-1062.66
linux-image-4.15.0-1067-aws –  4.15.0-1067.71
linux-image-4.15.0-1079-snapdragon –  4.15.0-1079.86
linux-image-4.15.0-1081-oem –  4.15.0-1081.91
linux-image-4.15.0-1083-azure –  4.15.0-1083.93
linux-image-aws-lts-18.04 –  4.15.0.1067.70
linux-image-azure-lts-18.04 –  4.15.0.1083.54
linux-image-generic –  4.15.0.101.91
linux-image-generic-lpae –  4.15.0.101.91
linux-image-gke –  4.15.0.1059.63
linux-image-gke-4.15 –  4.15.0.1059.63
linux-image-kvm –  4.15.0.1060.60
linux-image-lowlatency –  4.15.0.101.91
linux-image-oem –  4.15.0.1081.85
linux-image-oracle-lts-18.04 –  4.15.0.1039.48
linux-image-raspi2 –  4.15.0.1062.60
linux-image-snapdragon –  4.15.0.1079.82
linux-image-virtual –  4.15.0.101.91
16.04 xenial linux-image-4.15.0-101-generic –  4.15.0-101.102~16.04.1
linux-image-4.15.0-101-generic-lpae –  4.15.0-101.102~16.04.1
linux-image-4.15.0-101-lowlatency –  4.15.0-101.102~16.04.1
linux-image-4.15.0-1039-oracle –  4.15.0-1039.43~16.04.1
linux-image-4.15.0-1067-aws –  4.15.0-1067.71~16.04.1
linux-image-4.15.0-1071-gcp –  4.15.0-1071.81~16.04.1
linux-image-4.15.0-1083-azure –  4.15.0-1083.93~16.04.1
linux-image-aws-hwe –  4.15.0.1067.67
linux-image-azure –  4.15.0.1083.82
linux-image-azure-edge –  4.15.0.1083.82
linux-image-gcp –  4.15.0.1071.77
linux-image-generic-hwe-16.04 –  4.15.0.101.108
linux-image-generic-lpae-hwe-16.04 –  4.15.0.101.108
linux-image-gke –  4.15.0.1071.77
linux-image-lowlatency-hwe-16.04 –  4.15.0.101.108
linux-image-oem –  4.15.0.101.108
linux-image-oracle –  4.15.0.1039.32
linux-image-virtual-hwe-16.04 –  4.15.0.101.108

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References

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