USN-4463-1: Linux kernel vulnerabilities

18 August 2020

Several security issues were fixed in the Linux kernel.

Releases

Packages

Details

It was discovered that the bcache subsystem in the Linux kernel did not
properly release a lock in some error conditions. A local attacker could
possibly use this to cause a denial of service. (CVE-2020-12771)

Kyungtae Kim discovered that the USB testing driver in the Linux kernel did
not properly deallocate memory on disconnect events. A physically proximate
attacker could use this to cause a denial of service (memory exhaustion).
(CVE-2020-15393)

Update instructions

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

Ubuntu 16.04
Ubuntu 14.04

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-4485-1: linux-image-generic-lpae-hwe-16.04, linux-image-virtual-hwe-16.04, linux-oem, linux-image-4.15.0-1084-snapdragon, linux-gke-4.15, linux-image-4.15.0-1080-aws, linux-image-azure, linux-image-generic-hwe-16.04-edge, linux-image-oracle, linux-image-4.15.0-1072-kvm, linux-image-generic-hwe-16.04, linux, linux-image-oracle-lts-18.04, linux-image-snapdragon, linux-snapdragon, linux-image-lowlatency, linux-azure, linux-aws, linux-image-4.15.0-1051-oracle, linux-image-lowlatency-hwe-16.04-edge, linux-image-azure-edge, linux-image-gcp, linux-image-virtual-hwe-16.04-edge, linux-azure-4.15, linux-oracle, linux-image-gke-4.15, linux-image-generic, linux-image-generic-lpae-hwe-16.04-edge, linux-image-gke, linux-image-4.15.0-115-lowlatency, linux-image-4.15.0-115-generic, linux-image-4.15.0-1093-azure, linux-aws-hwe, linux-kvm, linux-gcp, linux-image-4.15.0-1081-gcp, linux-image-virtual, linux-image-4.15.0-1067-gke, linux-image-aws-lts-18.04, linux-image-aws-hwe, linux-image-kvm, linux-image-oem, linux-raspi2, linux-hwe, linux-image-4.15.0-115-generic-lpae, linux-image-generic-lpae, linux-image-4.15.0-1094-oem, linux-image-4.15.0-1068-raspi2, linux-image-azure-lts-18.04, linux-image-gcp-lts-18.04, linux-gcp-4.15, linux-image-lowlatency-hwe-16.04, linux-image-raspi2
  • USN-4462-1: linux-oem-osp1, linux-image-gke-5.0, linux-gke-5.0, linux-image-oem-osp1, linux-image-5.0.0-1067-oem-osp1, linux-image-5.0.0-1046-gke
  • USN-4483-1: linux-image-snapdragon-hwe-18.04-edge, linux-image-raspi-hwe-18.04, linux-image-raspi, linux-image-generic-hwe-20.04, linux-image-5.4.0-1016-raspi, linux-image-azure, linux-image-oracle, linux-raspi-5.4, linux-image-5.4.0-45-generic-lpae, linux, linux-image-raspi-hwe-18.04-edge, linux-raspi, linux-image-generic-lpae-hwe-20.04, linux-image-5.4.0-1022-oracle, linux-image-lowlatency, linux-azure, linux-image-aws-edge, linux-aws, linux-image-generic-lpae-hwe-18.04-edge, linux-image-raspi2-hwe-18.04, linux-image-lowlatency-hwe-20.04, linux-azure-5.4, linux-image-5.4.0-1023-azure, linux-image-5.4.0-45-lowlatency, linux-image-azure-edge, linux-image-gcp, linux-image-gke-5.4, linux-image-oem-osp1, linux-oracle, linux-image-5.4.0-1022-aws, linux-image-5.4.0-45-generic, linux-image-generic, linux-image-aws, linux-image-raspi2-hwe-18.04-edge, linux-image-gke, linux-image-virtual-hwe-18.04-edge, linux-image-generic-lpae-hwe-18.04, linux-gcp, linux-image-virtual-hwe-20.04, linux-image-gcp-edge, linux-aws-5.4, linux-image-generic-hwe-18.04-edge, linux-image-lowlatency-hwe-18.04-edge, linux-image-virtual, linux-image-kvm, linux-image-oem, linux-image-oracle-edge, linux-image-virtual-hwe-18.04, linux-image-generic-lpae, linux-oracle-5.4, linux-image-5.4.0-1022-gcp, linux-image-gkeop-5.4, linux-image-snapdragon-hwe-18.04, linux-image-generic-hwe-18.04, linux-gcp-5.4, linux-hwe-5.4, linux-image-lowlatency-hwe-18.04, linux-kvm, linux-image-raspi2
  • USN-4465-1: linux-image-gke-5.3, linux-hwe, linux-image-5.3.0-1033-gke, linux-image-5.3.0-65-generic, linux-gke-5.3, linux-image-gkeop-5.3, linux-image-azure, linux-image-5.3.0-1035-azure, linux-image-5.3.0-65-lowlatency, linux-image-5.3.0-1033-aws, linux-azure-5.3, linux-image-aws, linux-aws-5.3