USN-4324-1: Linux kernel vulnerabilities

USN-4324-1: Linux kernel vulnerabilities

linux-aws, linux-aws-hwe, linux-azure, linux-gcp, linux-gke-4.15, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

• Ubuntu 18.04 LTS
• Ubuntu 16.04 LTS
• Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the Linux kernel.

Software Description

• linux-aws – Linux kernel for Amazon Web Services (AWS) systems
• linux-gke-4.15 – Linux kernel for Google Container Engine (GKE) systems
• linux-kvm – Linux kernel for cloud environments
• linux-oem – Linux kernel for OEM processors
• linux-oracle – Linux kernel for Oracle Cloud systems
• linux-raspi2 – Linux kernel for Raspberry Pi 2
• linux-snapdragon – Linux kernel for 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

Details

Al Viro discovered that the vfs layer in the Linux kernel contained a use-
after-free vulnerability. A local attacker could use this to cause a denial
of service (system crash) or possibly expose sensitive information (kernel
memory). (CVE-2020-8428)

Shijie Luo discovered that the ext4 file system implementation in the Linux
kernel did not properly check for a too-large journal size. An attacker
could use this to construct a malicious ext4 image that, when mounted,
could cause a denial of service (soft lockup). (CVE-2020-8992)

Update instructions

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

Ubuntu 18.04 LTS

linux-image-4.15.0-1037-oracle – 4.15.0-1037.41

linux-image-4.15.0-1057-gke – 4.15.0-1057.60

linux-image-4.15.0-1058-kvm – 4.15.0-1058.59

linux-image-4.15.0-1060-raspi2 – 4.15.0-1060.64

linux-image-4.15.0-1065-aws – 4.15.0-1065.69

linux-image-4.15.0-1076-snapdragon – 4.15.0-1076.83

linux-image-4.15.0-1079-oem – 4.15.0-1079.89

linux-image-aws – 4.15.0.1065.67

linux-image-aws-lts-18.04 – 4.15.0.1065.67

linux-image-gke – 4.15.0.1057.61

linux-image-gke-4.15 – 4.15.0.1057.61

linux-image-kvm – 4.15.0.1058.58

linux-image-oem – 4.15.0.1079.83

linux-image-oracle-lts-18.04 – 4.15.0.1037.45

linux-image-raspi2 – 4.15.0.1060.58

linux-image-snapdragon – 4.15.0.1076.79

Ubuntu 16.04 LTS

linux-image-4.15.0-1037-oracle – 4.15.0-1037.41~16.04.1

linux-image-4.15.0-1060-gcp – 4.15.0-1060.64

linux-image-4.15.0-1065-aws – 4.15.0-1065.69~16.04.1

linux-image-4.15.0-1077-azure – 4.15.0-1077.82

linux-image-aws-hwe – 4.15.0.1065.65

linux-image-azure – 4.15.0.1077.80

linux-image-azure-edge – 4.15.0.1077.80

linux-image-gcp – 4.15.0.1060.74

linux-image-gke – 4.15.0.1060.74

linux-image-oracle – 4.15.0.1037.30

Ubuntu 14.04 ESM

linux-image-4.15.0-1077-azure – 4.15.0-1077.82~14.04.1

linux-image-azure – 4.15.0.1077.62

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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.

References

• CVE-2020-8428
• CVE-2020-8992

Source: USN-4324-1: Linux kernel vulnerabilities