Ubuntu 18.04 LTS: 4916-1 Critical: Kernel Escalation Threats

ubuntu

April 15, 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-raspi2: Linux kernel for Raspberry Pi (V8) 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

- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

It was discovered that the overlayfs implementation in the Linux kerne...

Read the Full Advisory

Topics Covered

security advisory denial of service critical issue kernel update critical privilege escalation Ubuntu system update kernel issue ubuntu linux kernel system reboot

Update Instructions

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1017-dell300x  4.15.0-1017.21
  linux-image-4.15.0-1070-oracle  4.15.0-1070.78
  linux-image-4.15.0-1084-raspi2  4.15.0-1084.89
  linux-image-4.15.0-1090-kvm     4.15.0-1090.92
  linux-image-4.15.0-1098-gcp     4.15.0-1098.111
  linux-image-4.15.0-1099-aws     4.15.0-1099.106
  linux-image-4.15.0-1101-snapdragon  4.15.0-1101.110
  linux-image-4.15.0-1113-azure   4.15.0-1113.126
  linux-image-4.15.0-142-generic  4.15.0-142.146
  linux-image-4.15.0-142-generic-lpae  4.15.0-142.146
  linux-image-4.15.0-142-lowlatency  4.15.0-142.146
  linux-image-aws-lts-18.04       4.15.0.1099.102
  linux-image-azure-lts-18.04     4.15.0.1113.86
  linux-image-dell300x            4.15.0.1017.19
  linux-image-gcp-lts-18.04       4.15.0.1098.116
  linux-image-generic             4.15.0.142.129
  linux-image-generic-lpae        4.15.0.142.129
  linux-image-kvm                 4.15.0.1090.86
  linux-image-lowlatency          4.15.0.142.129
  linux-image-oracle-lts-18.04    4.15.0.1070.80
  linux-image-powerpc-e500mc      4.15.0.142.129
  linux-image-powerpc-smp         4.15.0.142.129
  linux-image-powerpc64-emb       4.15.0.142.129
  linux-image-powerpc64-smp       4.15.0.142.129
  linux-image-raspi2              4.15.0.1084.81
  linux-image-snapdragon          4.15.0.1101.104
  linux-image-virtual             4.15.0.142.129

Ubuntu 16.04 LTS:
  linux-image-4.15.0-1070-oracle  4.15.0-1070.78~16.04.1
  linux-image-4.15.0-1098-gcp     4.15.0-1098.111~16.04.1
  linux-image-4.15.0-1099-aws     4.15.0-1099.106~16.04.1
  linux-image-4.15.0-1113-azure   4.15.0-1113.126~16.04.1
  linux-image-4.15.0-142-generic  4.15.0-142.146~16.04.1
  linux-image-4.15.0-142-generic-lpae  4.15.0-142.146~16.04.1
  linux-image-4.15.0-142-lowlatency  4.15.0-142.146~16.04.1
  linux-image-4.4.0-1092-kvm      4.4.0-1092.101
  linux-image-4.4.0-1127-aws      4.4.0-1127.141
  linux-image-4.4.0-1151-raspi2   4.4.0-1151.162
  linux-image-4.4.0-1155-snapdragon  4.4.0-1155.165
  linux-image-4.4.0-209-generic   4.4.0-209.241
  linux-image-4.4.0-209-generic-lpae  4.4.0-209.241
  linux-image-4.4.0-209-lowlatency  4.4.0-209.241
  linux-image-4.4.0-209-powerpc-e500mc  4.4.0-209.241
  linux-image-4.4.0-209-powerpc-smp  4.4.0-209.241
  linux-image-4.4.0-209-powerpc64-emb  4.4.0-209.241
  linux-image-4.4.0-209-powerpc64-smp  4.4.0-209.241
  linux-image-aws                 4.4.0.1127.132
  linux-image-aws-hwe             4.15.0.1099.92
  linux-image-azure               4.15.0.1113.104
  linux-image-gcp                 4.15.0.1098.99
  linux-image-generic             4.4.0.209.215
  linux-image-generic-hwe-16.04   4.15.0.142.137
  linux-image-generic-lpae        4.4.0.209.215
  linux-image-generic-lpae-hwe-16.04  4.15.0.142.137
  linux-image-gke                 4.15.0.1098.99
  linux-image-kvm                 4.4.0.1092.90
  linux-image-lowlatency          4.4.0.209.215
  linux-image-lowlatency-hwe-16.04  4.15.0.142.137
  linux-image-oem                 4.15.0.142.137
  linux-image-oracle              4.15.0.1070.58
  linux-image-powerpc-e500mc      4.4.0.209.215
  linux-image-powerpc-smp         4.4.0.209.215
  linux-image-powerpc64-emb       4.4.0.209.215
  linux-image-powerpc64-smp       4.4.0.209.215
  linux-image-raspi2              4.4.0.1151.151
  linux-image-snapdragon          4.4.0.1155.147
  linux-image-virtual             4.4.0.209.215
  linux-image-virtual-hwe-16.04   4.15.0.142.137

Ubuntu 14.04 ESM:
  linux-image-4.15.0-1113-azure   4.15.0-1113.126~14.04.1
  linux-image-4.4.0-1091-aws      4.4.0-1091.95
  linux-image-4.4.0-209-generic   4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-generic-lpae  4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-lowlatency  4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-powerpc-e500mc  4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-powerpc-smp  4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-powerpc64-emb  4.4.0-209.241~14.04.1
  linux-image-4.4.0-209-powerpc64-smp  4.4.0-209.241~14.04.1
  linux-image-aws                 4.4.0.1091.88
  linux-image-azure               4.15.0.1113.86
  linux-image-generic-lpae-lts-xenial  4.4.0.209.182
  linux-image-generic-lts-xenial  4.4.0.209.182
  linux-image-lowlatency-lts-xenial  4.4.0.209.182
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.209.182
  linux-image-powerpc-smp-lts-xenial  4.4.0.209.182
  linux-image-powerpc64-emb-lts-xenial  4.4.0.209.182
  linux-image-powerpc64-smp-lts-xenial  4.4.0.209.182
  linux-image-virtual-lts-xenial  4.4.0.209.182

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.