USN-4363-1: Linux kernel vulnerabilities

28 May 2020

Several security issues were fixed in the Linux kernel.



  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-4.15 - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-4.15 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oem - Linux kernel for OEM systems
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi (V7) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors


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)

It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)

David Gibson discovered that the Linux kernel on Power9 CPUs did not
properly save and restore Authority Mask registers state in some
situations. A local attacker in a guest VM could use this to cause a denial
of service (host system crash). (CVE-2020-11669)

It was discovered that the block layer in the Linux kernel contained a race
condition leading to a use-after-free vulnerability. A local attacker could
possibly use this to cause a denial of service (system crash) or execute
arbitrary code. (CVE-2020-12657)

Update instructions

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

Ubuntu 18.04
Ubuntu 16.04

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.

Related notices

  • USN-4364-1: linux-image-lowlatency-lts-xenial, linux-image-snapdragon, linux-image-virtual, linux-image-4.4.0-1107-aws, linux-image-generic-lpae, linux-image-aws, linux-snapdragon, linux-image-generic, linux-image-raspi2, linux-image-virtual-lts-xenial, linux-image-lowlatency, linux-lts-xenial, linux-image-4.4.0-1133-raspi2, linux-image-4.4.0-179-lowlatency, linux, linux-image-4.4.0-1067-aws, linux-image-powerpc64-emb, linux-image-generic-lts-xenial, linux-image-powerpc-smp, linux-image-4.4.0-179-powerpc-smp, linux-image-generic-lpae-lts-xenial, linux-image-4.4.0-1137-snapdragon, linux-image-4.4.0-179-powerpc-e500mc, linux-raspi2, linux-image-4.4.0-179-powerpc64-emb, linux-image-powerpc-e500mc, linux-image-powerpc64-smp-lts-xenial, linux-image-kvm, linux-image-4.4.0-1071-kvm, linux-image-powerpc64-emb-lts-xenial, linux-kvm, linux-image-4.4.0-179-generic-lpae, linux-image-powerpc-e500mc-lts-xenial, linux-image-powerpc64-smp, linux-image-4.4.0-179-powerpc64-smp, linux-image-4.4.0-179-generic, linux-image-powerpc-smp-lts-xenial, linux-aws
  • USN-4368-1: linux-image-5.0.0-1052-oem-osp1, linux-gke-5.0, linux-image-5.0.0-1037-gke, linux-image-oem-osp1, linux-oem-osp1, linux-image-gke-5.0
  • USN-4367-1: linux-image-5.4.0-1011-gcp, linux-image-virtual, linux-image-oem-osp1, linux-image-generic-lpae, linux-image-aws, linux-image-generic, linux-image-5.4.0-1011-aws, linux-image-raspi2, linux-image-lowlatency, linux-image-5.4.0-31-generic-lpae, linux-image-5.4.0-1011-oracle, linux, linux-gcp, linux-riscv, linux-image-gke, linux-oracle, linux-raspi, linux-azure, linux-image-gcp, linux-image-oracle, linux-image-raspi, linux-image-kvm, linux-kvm, linux-image-5.4.0-1012-azure, linux-image-5.4.0-1011-raspi, linux-image-azure, linux-image-5.4.0-1011-kvm, linux-image-5.4.0-26-generic, linux-image-5.4.0-31-generic, linux-image-5.4.0-31-lowlatency, linux-image-oem, linux-aws
  • USN-4369-1: linux-image-snapdragon, linux-image-virtual, linux-image-generic-lpae, linux-image-5.3.0-1022-azure, linux-image-5.3.0-1019-aws, linux-image-aws, linux-image-generic, linux-image-raspi2, linux-azure-5.3, linux-image-lowlatency, linux-image-lowlatency-hwe-18.04, linux-hwe, linux-image-azure-edge, linux-aws-5.3, linux, linux-gke-5.3, linux-gcp, linux-aws, linux-image-gkeop-5.3, linux-image-gke-5.3, linux-image-generic-hwe-18.04, linux-image-5.3.0-1017-kvm, linux-image-gke, linux-oracle, linux-oracle-5.3, linux-image-generic-lpae-hwe-18.04, linux-azure, linux-image-gcp, linux-image-5.3.0-1025-raspi2, linux-raspi2, linux-image-5.3.0-53-lowlatency, linux-image-oracle, linux-gcp-5.3, linux-image-snapdragon-hwe-18.04, linux-image-kvm, linux-image-virtual-hwe-18.04, linux-image-5.3.0-53-generic, linux-kvm, linux-image-5.3.0-53-generic-lpae, linux-image-azure, linux-image-aws-edge, linux-image-5.3.0-53-snapdragon, linux-image-5.3.0-1018-oracle, linux-image-gcp-edge, linux-image-5.3.0-1020-gcp, linux-image-5.3.0-1020-gke