Ubuntu 18.04 LTS USN-5985-1 Critical: Kernel Denial Of Service Risks

ubuntu

March 29, 2023

Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems

- linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems

- linux-gcp-5.4: Linux kernel for Google Cloud Platform (GCP) systems

- linux-hwe-5.4: Linux hardware enablement (HWE) kernel

- linux-ibm-5.4: Linux kernel for IBM cloud systems

- linux-oracle-5.4: Linux kernel for Oracle Cloud systems

- linux-raspi-5.4: Linux kernel for Raspberry Pi systems

Details:

It was discovered that the System V IPC implementation in the Linux kernel

did not properly handle large shared memory counts. A local attacker could

use this to cause a denial of service (memory exhaustion). (CVE-2021-3669)

It was discovered that the KVM VMX implementation in the Linux kernel did

not properly handle indirect branch prediction isolation between L1 and L2

VMs. An attacker in a guest VM could use this to expose sensitive

information from ...

Read the Full Advisory

Topics Covered

security advisory critical ubuntu memory exhaustion system crash cloud vulnerabilities kernel denial of service

Update Instructions

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

Ubuntu 18.04 LTS:
   linux-image-5.4.0-1046-ibm      5.4.0-1046.51~18.04.1
   linux-image-5.4.0-1082-raspi    5.4.0-1082.93~18.04.1
   linux-image-5.4.0-1098-oracle   5.4.0-1098.107~18.04.1
   linux-image-5.4.0-1099-aws      5.4.0-1099.107~18.04.1
   linux-image-5.4.0-1102-gcp      5.4.0-1102.111~18.04.2
   linux-image-5.4.0-1105-azure    5.4.0-1105.111~18.04.1
   linux-image-5.4.0-146-generic   5.4.0-146.163~18.04.1
   linux-image-5.4.0-146-generic-lpae  5.4.0-146.163~18.04.1
   linux-image-5.4.0-146-lowlatency  5.4.0-146.163~18.04.1
   linux-image-aws                 5.4.0.1099.77
   linux-image-azure               5.4.0.1105.78
   linux-image-gcp                 5.4.0.1102.78
   linux-image-generic-hwe-18.04   5.4.0.146.163~18.04.117
   linux-image-generic-lpae-hwe-18.04  5.4.0.146.163~18.04.117
   linux-image-ibm                 5.4.0.1046.57
   linux-image-lowlatency-hwe-18.04  5.4.0.146.163~18.04.117
   linux-image-oem                 5.4.0.146.163~18.04.117
   linux-image-oem-osp1            5.4.0.146.163~18.04.117
   linux-image-oracle              5.4.0.1098.107~18.04.70
   linux-image-raspi-hwe-18.04     5.4.0.1082.79
   linux-image-snapdragon-hwe-18.04  5.4.0.146.163~18.04.117
   linux-image-virtual-hwe-18.04   5.4.0.146.163~18.04.117

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.