USN-4412-1: Linux kernel vulnerabilities

06 July 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-aws-5.3 - 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-raspi2-5.3 - Linux kernel for Raspberry Pi (V7) systems

Details

Matthew Sheets discovered that the SELinux network label handling
implementation in the Linux kernel could be coerced into de-referencing a
NULL pointer. A remote attacker could use this to cause a denial of service
(system crash). (CVE-2020-10711)

It was discovered that the SCSI generic (sg) driver in the Linux kernel did
not properly handle certain error conditions correctly. A local privileged
attacker could use this to cause a denial of service (system crash).
(CVE-2020-12770)

It was discovered that the USB Gadget device driver in the Linux kernel did
not validate arguments passed from configfs in some situations. A local
attacker could possibly use this to cause a denial of service (system
crash) or possibly expose sensitive information. (CVE-2020-13143)

Dmitry Vyukov discovered that the SELinux netlink security hook in the
Linux kernel did not validate messages in some situations. A privileged
attacker could use this to bypass SELinux netlink restrictions.
(CVE-2020-10751)

It was discovered that the KVM implementation in the Linux kernel did not
properly deallocate memory on initialization for some processors. A local
attacker could possibly use this to cause a denial of service.
(CVE-2020-12768)

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.