A linux kernel security update has been released for Ubuntu Linux 14.04 ESM, 16.04 LTS, 18.04 LTS, and 20.04 LTS.

LSN-0072-1: linux kernel vulnerability

Linux kernel vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the kernel.

Software Description

- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems - linux-azure - Linux kernel for Microsoft Azure Cloud systems - linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems - linux-oem - Linux kernel for OEM systems

Details

It was discovered that the F2FS file system implementation in the Linux kernel did not properly perform bounds checking on xattrs in some situations. A local attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2020-0067)

It was discovered that the Serial CAN interface driver in the Linux kernel did not properly initialize data. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-11494)
Mauricio Faria de Oliveira discovered that the aufs implementation in the Linux kernel improperly managed inode reference counts in the vfsub_dentry_open() method. A local attacker could use this
vulnerability to cause a denial of service. (CVE-2020-11935)
Piotr Krysiuk discovered that race conditions existed in the file system implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-12114)

Or Cohen discovered that the AF_PACKET implementation in the Linux kernel did not properly perform bounds checking in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-14386)

Hador Manor discovered that the DCCP protocol implementation in the Linux kernel improperly handled socket reuse, leading to a
use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Giuseppe Scrivano discovered that the overlay file system in the Linux kernel did not properly perform permission checks in some situations. A local attacker could possibly use this to bypass intended restrictions and gain read access to restricted files. (CVE-2020-16120)

Update instructions

The problem can be corrected by updating your kernel livepatch to the following versions:

Ubuntu 18.04 LTS
aws - 72.1
generic - 72.1
lowlatency - 72.1
oem - 72.1

Ubuntu 20.04 LTS
aws - 72.1
aws - 72.2
azure - 72.1
azure - 72.2
gcp - 72.1
gcp - 72.2
generic - 72.1
generic - 72.2
lowlatency - 72.1
lowlatency - 72.2

Ubuntu 16.04 LTS
aws - 72.1
generic - 72.1
lowlatency - 72.1

Ubuntu 14.04 ESM
generic - 72.1
lowlatency - 72.1

Support Information

Kernels older than the levels listed below do not receive livepatch updates. If you are running a kernel version earlier than the one listed below, please upgrade your kernel as soon as possible.

Ubuntu 18.04 LTS
linux-aws - 4.15.0-1054
linux-azure - 5.0.0-1025
linux-gcp - 5.0.0-1025
linux-oem - 4.15.0-1063
linux-oracle - 5.0.0-1000
linux - 4.15.0-69

Ubuntu 20.04 LTS
linux-aws - 5.4.0-1009
linux-azure - 5.4.0-1010
linux-gcp - 5.4.0-1009
linux-oem - 5.4.0-26
linux - 5.4.0-26

Ubuntu 16.04 LTS
linux-aws - 4.4.0-1098
linux-azure - 4.15.0-1063
linux-hwe - 4.15.0-69
linux - 4.4.0-168

Ubuntu 14.04 ESM
linux-lts-xenial - 4.4.0-168

References

- CVE-2020-0067
- CVE-2020-11494
- CVE-2020-11935
- CVE-2020-12114
- CVE-2020-14386
- CVE-2020-16119
- CVE-2020-16120