1. Ubuntu Security Notices
  2. USN-4890-1

USN-4890-1: Linux kernel vulnerabilities

Publication date

29 March 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-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-dell300x - Linux kernel for Dell 300x platforms
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-4.15 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly compute a speculative execution limit on pointer arithmetic in
some situations. A local attacker could use this to expose sensitive
information (kernel memory). (CVE-2020-27171)

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly apply speculative execution limits on some pointer types. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2020-27170)

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly compute a speculative execution limit on pointer arithmetic in
some situations. A local attacker could use this to expose sensitive
information (kernel memory). (CVE-2020-27171)

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly apply speculative execution limits on some pointer types. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2020-27170)

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-dell300x –  4.15.0-1015.19
linux-image-4.15.0-1068-oracle –  4.15.0-1068.76
linux-image-4.15.0-1082-raspi2 –  4.15.0-1082.87
linux-image-4.15.0-1088-kvm –  4.15.0-1088.90
linux-image-4.15.0-1096-gcp –  4.15.0-1096.109
linux-image-4.15.0-1097-aws –  4.15.0-1097.104
linux-image-4.15.0-1099-snapdragon –  4.15.0-1099.108
linux-image-4.15.0-1111-azure –  4.15.0-1111.123
linux-image-4.15.0-140-generic –  4.15.0-140.144
linux-image-4.15.0-140-generic-lpae –  4.15.0-140.144
linux-image-4.15.0-140-lowlatency –  4.15.0-140.144
linux-image-aws-lts-18.04 –  4.15.0.1097.100
linux-image-azure-lts-18.04 –  4.15.0.1111.84
linux-image-dell300x –  4.15.0.1015.17
linux-image-gcp-lts-18.04 –  4.15.0.1096.114
linux-image-generic –  4.15.0.140.127
linux-image-generic-lpae –  4.15.0.140.127
linux-image-kvm –  4.15.0.1088.84
linux-image-lowlatency –  4.15.0.140.127
linux-image-oracle-lts-18.04 –  4.15.0.1068.78
linux-image-raspi2 –  4.15.0.1082.79
linux-image-snapdragon –  4.15.0.1099.102
linux-image-virtual –  4.15.0.140.127
16.04 xenial linux-image-4.15.0-1068-oracle –  4.15.0-1068.76~16.04.1
linux-image-4.15.0-1096-gcp –  4.15.0-1096.109~16.04.1
linux-image-4.15.0-1097-aws –  4.15.0-1097.104~16.04.1
linux-image-4.15.0-1111-azure –  4.15.0-1111.123~16.04.1
linux-image-4.15.0-140-generic –  4.15.0-140.144~16.04.1
linux-image-4.15.0-140-generic-lpae –  4.15.0-140.144~16.04.1
linux-image-4.15.0-140-lowlatency –  4.15.0-140.144~16.04.1
linux-image-aws-hwe –  4.15.0.1097.90
linux-image-azure –  4.15.0.1111.102
linux-image-gcp –  4.15.0.1096.97
linux-image-generic-hwe-16.04 –  4.15.0.140.135
linux-image-generic-lpae-hwe-16.04 –  4.15.0.140.135
linux-image-gke –  4.15.0.1096.97
linux-image-lowlatency-hwe-16.04 –  4.15.0.140.135
linux-image-oem –  4.15.0.140.135
linux-image-oracle –  4.15.0.1068.56
linux-image-virtual-hwe-16.04 –  4.15.0.140.135
14.04 trusty linux-image-4.15.0-1111-azure –  4.15.0-1111.123~14.04.1
linux-image-azure –  4.15.0.1111.84

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References

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