Ubuntu 18.04 LTS: USN-4890-1 Critical: Linux Kernel Information Exposure

ubuntu

March 24, 2021

Several security issues were fixed in the Linux kernel.

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-4.15: Linux kernel for Microsoft Azure Cloud systems

- linux-dell300x: Linux kernel for Dell 300x platforms

- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems

- linux-kvm: Linux kernel for cloud environments

- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems

- linux-azure: Linux kernel for Microsoft Azure Cloud systems

- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

- linux-hwe: Linux hardware enablement (HWE) kernel

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 expos...

Read the Full Advisory

Topics Covered

security advisory security issue kernel update critical information exposure ubuntu linux kernel

Update Instructions

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

Ubuntu 18.04 LTS:
  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-4.15.0-1088-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-powerpc-e500mc      4.15.0.140.127
  linux-image-powerpc-smp         4.15.0.140.127
  linux-image-powerpc64-emb       4.15.0.140.127
  linux-image-powerpc64-smp       4.15.0.140.127
  linux-image-snapdragon          4.15.0.1099.102
  linux-image-virtual             4.15.0.140.127

Ubuntu 16.04 LTS:
  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

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.