1. Ubuntu Security Notices
  2. USN-5017-1

USN-5017-1: Linux kernel vulnerabilities

Publication date

20 July 2021

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-5.4 - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-5.4 - Linux kernel for Microsoft Azure cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-5.4 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-gke-5.4 - Linux kernel for Google Container Engine (GKE) systems
  • linux-gkeop - Linux kernel for Google Container Engine (GKE) systems
  • linux-gkeop-5.4 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe-5.4 - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-oracle-5.4 - Linux kernel for Oracle Cloud systems
  • linux-raspi - Linux kernel for Raspberry Pi (V8) systems
  • linux-raspi-5.4 - Linux kernel for Raspberry Pi (V8) systems

Details

It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2021-33909)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly perform access control. An authenticated attacker could possibly
use this to expose sensitive information. (CVE-2020-26558, CVE-2021-0129)

It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2021-33909)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly perform access control. An authenticated attacker could possibly
use this to expose sensitive information. (CVE-2020-26558, CVE-2021-0129)

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
20.04 focal linux-image-5.4.0-80-generic-lpae –  5.4.0-80.90
linux-image-gkeop –  5.4.0.1021.24
linux-image-virtual –  5.4.0.80.84
linux-image-generic –  5.4.0.80.84
linux-image-oem –  5.4.0.80.84
linux-image-5.4.0-1052-oracle –  5.4.0-1052.56
linux-image-5.4.0-1049-gke –  5.4.0-1049.52
linux-image-oem-osp1 –  5.4.0.80.84
linux-image-5.4.0-80-generic –  5.4.0-80.90
linux-image-5.4.0-1054-aws –  5.4.0-1054.57
linux-image-5.4.0-1049-gcp –  5.4.0-1049.53
linux-image-azure-lts-20.04 –  5.4.0.1055.53
linux-image-gkeop-5.4 –  5.4.0.1021.24
linux-image-lowlatency –  5.4.0.80.84
linux-image-gke –  5.4.0.1049.59
linux-image-aws-lts-20.04 –  5.4.0.1054.57
linux-image-raspi2 –  5.4.0.1041.76
linux-image-5.4.0-80-lowlatency –  5.4.0-80.90
linux-image-gcp-lts-20.04 –  5.4.0.1049.59
linux-image-oracle-lts-20.04 –  5.4.0.1052.52
linux-image-raspi –  5.4.0.1041.76
linux-image-5.4.0-1044-kvm –  5.4.0-1044.46
linux-image-5.4.0-1055-azure –  5.4.0-1055.57
linux-image-gke-5.4 –  5.4.0.1049.59
linux-image-kvm –  5.4.0.1044.43
linux-image-5.4.0-1021-gkeop –  5.4.0-1021.22
linux-image-generic-lpae –  5.4.0.80.84
linux-image-5.4.0-1041-raspi –  5.4.0-1041.45
18.04 bionic linux-image-gkeop-5.4 –  5.4.0.1021.22~18.04.22
linux-image-generic-hwe-18.04 –  5.4.0.80.90~18.04.72
linux-image-snapdragon-hwe-18.04 –  5.4.0.80.90~18.04.72
linux-image-5.4.0-80-generic-lpae –  5.4.0-80.90~18.04.1
linux-image-oem –  5.4.0.80.90~18.04.72
linux-image-aws –  5.4.0.1054.37
linux-image-5.4.0-1052-oracle –  5.4.0-1052.56~18.04.1
linux-image-raspi-hwe-18.04 –  5.4.0.1041.44
linux-image-oem-osp1 –  5.4.0.80.90~18.04.72
linux-image-5.4.0-80-generic –  5.4.0-80.90~18.04.1
linux-image-generic-lpae-hwe-18.04 –  5.4.0.80.90~18.04.72
linux-image-5.4.0-1054-aws –  5.4.0-1054.57~18.04.1
linux-image-5.4.0-1049-gcp –  5.4.0-1049.53~18.04.1
linux-image-5.4.0-1049-gke –  5.4.0-1049.52~18.04.1
linux-image-azure –  5.4.0.1055.35
linux-image-virtual-hwe-18.04 –  5.4.0.80.90~18.04.72
linux-image-5.4.0-1041-raspi –  5.4.0-1041.45~18.04.1
linux-image-gcp –  5.4.0.1049.36
linux-image-5.4.0-80-lowlatency –  5.4.0-80.90~18.04.1
linux-image-oracle –  5.4.0.1052.56~18.04.32
linux-image-lowlatency-hwe-18.04 –  5.4.0.80.90~18.04.72
linux-image-5.4.0-1055-azure –  5.4.0-1055.57~18.04.1
linux-image-gke-5.4 –  5.4.0.1049.52~18.04.15
linux-image-5.4.0-1021-gkeop –  5.4.0-1021.22~18.04.1

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References

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