LSN-0069-1: Kernel Live Patch Security Notice

27 July 2020

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

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

Relay_open in kernel/relay.c in the Linux kernel through 5.4.1 allows local users to cause a denial of service (such as relay blockage) by triggering a NULL alloc_percpu result. (CVE-2019-19462)

Fan Yang discovered that the mremap implementation in the Linux kernel did not properly handle DAX Huge Pages. A local attacker with access to DAX storage could use this to gain administrative privileges. (CVE-2020-10757)

It was discovered that the DesignWare SPI controller driver in the Linux kernel contained a race condition. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-12769)

In the Linux kernel before 5.4.16, a race condition in tty->disc_data handling in the slip and slcan line discipline could lead to a use-after-free, aka CID-0ace17d56824. This affects drivers/net/slip/slip.c and drivers/net/can/slcan.c. (CVE-2020-14416)

Update instructions

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

Ubuntu 18.04 LTS
aws - 69.1
generic - 69.1
lowlatency - 69.1
oem - 69.1
Ubuntu 20.04 LTS
aws - 69.1
azure - 69.1
gcp - 69.1
generic - 69.1
lowlatency - 69.1
Ubuntu 16.04 LTS
aws - 69.1
generic - 69.1
lowlatency - 69.1

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 - 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

References