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USN-4426-1: Linux kernel vulnerabilities

27 July 2020

Several security issues were fixed in the Linux kernel.

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Releases

Packages

  • 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-gcp-4.15 - 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

Details

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading SSDT code from an EFI variable. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2019-20908)

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)

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)

Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading ACPI tables via configfs. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2020-15780)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

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-4427-1: linux-image-lowlatency-lts-vivid, linux-image-generic-lts-utopic, linux-image-4.4.0-186-powerpc-e500mc, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc64-smp, linux-snapdragon, linux-image-powerpc64-emb-lts-xenial, linux-image-powerpc64-emb, linux-image-powerpc64-emb-lts-utopic, linux-image-snapdragon, linux-lts-xenial, linux-image-4.4.0-1136-raspi2, linux-image-4.4.0-1140-snapdragon, linux-image-generic-lts-xenial, linux-image-powerpc-e500mc-lts-utopic, linux-image-generic-lpae-lts-utopic, linux-image-powerpc-e500mc, linux-image-4.4.0-186-lowlatency, linux-image-4.4.0-1075-aws, linux-image-lowlatency, linux-raspi2, linux-image-4.4.0-186-powerpc64-smp, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-smp-lts-wily, linux-image-generic, linux-aws, linux-image-generic-lpae-lts-vivid, linux-image-virtual-lts-utopic, linux-image-generic-lpae, linux-image-4.4.0-186-powerpc-smp, linux, linux-image-aws, linux-image-virtual-lts-wily, linux-image-lowlatency-lts-xenial, linux-image-generic-lts-wily, linux-image-powerpc64-smp-lts-vivid, linux-image-virtual-lts-xenial, linux-image-powerpc64-emb-lts-wily, linux-image-generic-lpae-lts-wily, linux-kvm, linux-image-powerpc-e500mc-lts-wily, linux-image-raspi2, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc-smp-lts-vivid, linux-image-4.4.0-186-powerpc64-emb, linux-image-powerpc64-emb-lts-vivid, linux-image-virtual-lts-vivid, linux-image-virtual, linux-image-4.4.0-1077-kvm, linux-image-powerpc-e500mc-lts-vivid, linux-image-generic-lpae-lts-xenial, linux-image-powerpc-smp, linux-image-powerpc-smp-lts-wily, linux-image-4.4.0-1111-aws, linux-image-powerpc64-smp-lts-utopic, linux-image-lowlatency-lts-wily, linux-image-4.4.0-186-generic-lpae, linux-image-lowlatency-lts-utopic, linux-image-kvm, linux-image-generic-lts-vivid, linux-image-powerpc-e500mc-lts-xenial, linux-image-4.4.0-186-generic
  • USN-4439-1: linux-gke-5.0, linux-image-gke-5.0, linux-oem-osp1, linux-image-5.0.0-1045-gke, linux-image-5.0.0-1065-oem-osp1, linux-image-oem-osp1
  • USN-4440-1: linux-hwe, linux-image-5.3.0-64-lowlatency, linux-aws-5.3, linux-image-5.3.0-1030-raspi2, linux-image-5.3.0-64-generic-lpae, linux-image-oracle, linux-image-aws, linux-oracle-5.3, linux-image-gkeop-5.3, linux-image-5.3.0-1034-azure, linux-azure-5.3, linux-image-5.3.0-1032-gke, linux-image-5.3.0-1032-gcp, linux-gke-5.3, linux-image-5.3.0-1032-aws, linux-raspi2-5.3, linux-image-azure, linux-image-5.3.0-64-generic, linux-image-raspi2-hwe-18.04, linux-image-gcp, linux-image-5.3.0-1030-oracle, linux-gcp-5.3, linux-image-gke-5.3
  • USN-4483-1: linux-hwe-5.4, linux-image-5.4.0-1016-raspi, linux-image-raspi, linux-image-virtual-hwe-18.04, linux-image-generic-lpae-hwe-18.04, linux-image-snapdragon-hwe-18.04-edge, linux-raspi-5.4, linux-image-generic-hwe-20.04, linux-image-oem, linux-image-raspi-hwe-18.04, linux-image-generic-hwe-18.04-edge, linux-image-oem-osp1, linux-image-lowlatency, linux-image-generic-hwe-18.04, linux-image-5.4.0-1022-aws, linux-aws, linux-oracle, linux-gcp-5.4, linux-image-lowlatency-hwe-18.04, linux-image-aws-edge, linux-image-generic-lpae, linux, linux-image-aws, linux-image-5.4.0-1022-oracle, linux-image-oracle, linux-azure-5.4, linux-image-gke-5.4, linux-image-virtual-hwe-20.04, linux-image-azure-edge, linux-raspi, linux-oracle-5.4, linux-image-snapdragon-hwe-18.04, linux-kvm, linux-image-gke, linux-image-raspi2, linux-image-5.4.0-1022-gcp, linux-image-generic-lpae-hwe-20.04, linux-image-gcp-edge, linux-image-virtual, linux-azure, linux-image-azure, linux-gcp, linux-image-lowlatency-hwe-18.04-edge, linux-aws-5.4, linux-image-generic-lpae-hwe-18.04-edge, linux-image-raspi2-hwe-18.04, linux-image-raspi2-hwe-18.04-edge, linux-image-5.4.0-45-generic, linux-image-5.4.0-45-lowlatency, linux-image-lowlatency-hwe-20.04, linux-image-gcp, linux-image-5.4.0-45-generic-lpae, linux-image-virtual-hwe-18.04-edge, linux-image-oracle-edge, linux-image-raspi-hwe-18.04-edge, linux-image-gkeop-5.4, linux-image-kvm, linux-image-5.4.0-1023-azure, linux-image-generic
  • LSN-0069-1: aws, generic-4.15, generic-4.4, oem, lowlatency-4.15, generic-5.4, lowlatency-4.4, azure, lowlatency-5.4, gcp
  • USN-4425-1: linux-hwe-5.4, linux-image-raspi, linux-image-5.4.0-1022-azure, linux-image-generic-lpae-hwe-18.04, linux-image-virtual-hwe-18.04, linux-image-snapdragon-hwe-18.04-edge, linux-raspi-5.4, linux-image-generic-hwe-20.04, linux-image-oem, linux-image-raspi-hwe-18.04, linux-image-generic-hwe-18.04-edge, linux-image-oem-osp1, linux-image-lowlatency, linux-image-generic-hwe-18.04, linux-image-5.4.0-42-generic-lpae, linux-aws, linux-oracle, linux-image-5.4.0-30-generic, linux-image-lowlatency-hwe-18.04, linux-image-generic-lpae, linux-image-5.4.0-42-generic, linux, linux-image-aws, linux-image-oracle, linux-image-virtual-hwe-20.04, linux-azure-5.4, linux-raspi, linux-riscv, linux-image-snapdragon-hwe-18.04, linux-kvm, linux-image-gke, linux-image-raspi2, linux-image-5.4.0-1021-gcp, linux-image-5.4.0-1021-oracle, linux-image-generic-lpae-hwe-20.04, linux-image-virtual, linux-azure, linux-image-azure, linux-gcp, linux-image-lowlatency-hwe-18.04-edge, linux-image-5.4.0-1015-raspi, linux-image-generic-lpae-hwe-18.04-edge, linux-image-5.4.0-1020-aws, linux-image-raspi2-hwe-18.04, linux-image-raspi2-hwe-18.04-edge, linux-image-lowlatency-hwe-20.04, linux-image-gcp, linux-image-virtual-hwe-18.04-edge, linux-image-raspi-hwe-18.04-edge, linux-image-5.4.0-42-lowlatency, linux-image-gkeop-5.4, linux-image-kvm, linux-image-azure-edge, linux-image-generic
  • LSN-0070-1: aws, generic-4.15, generic-4.4, oem, lowlatency-4.15, generic-5.4, lowlatency-4.4, azure, lowlatency-5.4, gcp
  • LSN-0072-1: aws, generic-4.15, generic-4.4, oem, lowlatency-4.15, generic-5.4, lowlatency-4.4, azure, lowlatency-5.4, gcp