USN-4342-1: Linux kernel vulnerabilities

30 April 2020

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-5.3 - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-5.3 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-5.3 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-oracle-5.3 - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-raspi2-5.3 - Linux kernel for Raspberry Pi 2

Details

Al Viro discovered that the Linux kernel for s390x systems did not properly
perform page table upgrades for kernel sections that use secondary address
mode. A local attacker could use this to cause a denial of service (system
crash) or execute arbitrary code. (CVE-2020-11884)

It was discovered that the Intel Wi-Fi driver in the Linux kernel did not
properly check for errors in some situations. A local attacker could
possibly use this to cause a denial of service (system crash).
(CVE-2019-16234)

Tristan Madani discovered that the block I/O tracing implementation in the
Linux kernel contained a race condition. A local attacker could use this to
cause a denial of service (system crash) or possibly expose sensitive
information. (CVE-2019-19768)

It was discovered that the vhost net driver in the Linux kernel contained a
stack buffer overflow. A local attacker with the ability to perform ioctl()
calls on /dev/vhost-net could use this to cause a denial of service (system
crash). (CVE-2020-10942)

It was discovered that the virtual terminal implementation in the Linux
kernel contained a race condition. A local attacker could possibly use this
to cause a denial of service (system crash) or expose sensitive
information. (CVE-2020-8648)

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)

Jordy Zomer discovered that the floppy driver in the Linux kernel did not
properly check for errors in some situations. A local attacker could
possibly use this to cause a denial of service (system crash) or possibly
expose sensitive information. (CVE-2020-9383)

Update instructions

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

Ubuntu 19.10
Ubuntu 18.04

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.