USN-4681-1: Linux kernel vulnerabilities

06 January 2021

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-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
  • linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

Ryan Hall discovered that the Intel 700 Series Ethernet Controllers driver
in the Linux kernel did not properly deallocate memory in some conditions.
A local attacker could use this to cause a denial of service (kernel memory
exhaustion). (CVE-2019-0148)

It was discovered that the console keyboard driver in the Linux kernel
contained a race condition. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race
conditions when handling fonts. A local attacker could possibly use this to
expose sensitive information (kernel memory). (CVE-2020-25668)

Jinoh Kang discovered that the Xen event channel infrastructure in the
Linux kernel contained a race condition. An attacker in guest could
possibly use this to cause a denial of service (dom0 crash).
(CVE-2020-27675)

Minh Yuan discovered that the framebuffer console driver in the Linux
kernel did not properly handle fonts in some conditions. A local attacker
could use this to cause a denial of service (system crash) or possibly
expose sensitive information (kernel memory). (CVE-2020-28974)

It was discovered that Power 9 processors could be coerced to expose
information from the L1 cache in certain situations. A local attacker could
use this to expose sensitive information. (CVE-2020-4788)

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-4657-1: linux-image-powerpc64-smp, linux-image-virtual, linux-image-powerpc64-smp-lts-xenial, linux-image-lowlatency-lts-xenial, linux-image-4.4.0-197-lowlatency, linux-image-4.4.0-197-powerpc-smp, linux-image-powerpc64-emb-lts-xenial, linux-snapdragon, linux-image-aws, linux-image-4.4.0-197-powerpc64-emb, linux-image-4.4.0-197-powerpc64-smp, linux-image-generic-lpae-lts-xenial, linux-lts-xenial, linux-image-4.4.0-197-generic-lpae, linux-raspi2, linux-aws, linux-image-powerpc-smp-lts-xenial, linux-image-lowlatency, linux-image-snapdragon, linux-image-powerpc-e500mc, linux-image-powerpc64-emb, linux-image-generic-lpae, linux-image-kvm, linux-image-raspi2, linux-image-powerpc-e500mc-lts-xenial, linux-image-4.4.0-1146-snapdragon, linux-image-4.4.0-1118-aws, linux-image-4.4.0-197-generic, linux, linux-image-4.4.0-1084-kvm, linux-kvm, linux-image-powerpc-smp, linux-image-4.4.0-1142-raspi2, linux-image-virtual-lts-xenial, linux-image-generic-lts-xenial, linux-image-4.4.0-1082-aws, linux-image-4.4.0-197-powerpc-e500mc, linux-image-generic
  • USN-4680-1: linux-image-4.15.0-1062-oracle, linux-image-powerpc64-smp, linux-gcp, linux-image-oracle-lts-18.04, linux-image-4.15.0-129-generic, linux-image-aws-hwe, linux-image-virtual, linux-image-4.15.0-129-generic-lpae, linux-aws-hwe, linux-image-4.15.0-1091-gcp, linux-image-4.15.0-129-lowlatency, linux-gcp-4.15, linux-image-azure, linux-azure-4.15, linux-image-gke, linux-image-4.15.0-1082-kvm, linux-snapdragon, linux-image-4.15.0-1077-gke, linux-azure, linux-image-gcp-lts-18.04, linux-raspi2, linux-image-4.15.0-1091-aws, linux-hwe, linux-aws, linux-image-4.15.0-1077-raspi2, linux-gke-4.15, linux-image-lowlatency, linux-image-snapdragon, linux-image-powerpc-e500mc, linux-image-powerpc64-emb, linux-image-generic-lpae, linux-image-kvm, linux-image-4.15.0-1094-snapdragon, linux-image-raspi2, linux-oracle, linux-image-4.15.0-1103-azure, linux, linux-image-azure-lts-18.04, linux-image-generic-hwe-16.04, linux-image-aws-lts-18.04, linux-image-generic-lpae-hwe-16.04, linux-image-lowlatency-hwe-16.04, linux-image-powerpc-smp, linux-image-virtual-hwe-16.04, linux-kvm, linux-image-gcp, linux-image-oracle, linux-image-gke-4.15, linux-image-oem, linux-image-generic
  • USN-4679-1: linux-gcp, linux-hwe-5.4, linux-raspi-5.4, linux-image-gke-5.4, linux-gke-5.4, linux-image-5.4.0-1033-gke, linux-image-5.4.0-1035-azure, linux-image-virtual, linux-image-5.4.0-1034-aws, linux-image-virtual-hwe-18.04, linux-image-azure, linux-image-5.4.0-1033-gcp, linux-image-aws, linux-image-5.4.0-59-generic-lpae, linux-azure, linux-image-5.4.0-1034-oracle, linux-aws, linux-gcp-5.4, linux-image-lowlatency, linux-image-raspi-hwe-18.04, linux-image-generic-lpae, linux-image-kvm, linux-image-5.4.0-1026-raspi, linux-image-generic-hwe-18.04, linux-image-raspi2, linux-image-oem-osp1, linux-oracle, linux-raspi, linux-oracle-5.4, linux, linux-image-generic-lpae-hwe-18.04, linux-image-5.4.0-59-lowlatency, linux-image-5.4.0-59-generic, linux-image-raspi, linux-azure-5.4, linux-image-5.4.0-1031-kvm, linux-kvm, linux-image-lowlatency-hwe-18.04, linux-image-gcp, linux-image-snapdragon-hwe-18.04, linux-image-oracle, linux-image-oem, linux-aws-5.4, linux-image-generic
  • USN-4659-1: linux-gcp, linux-image-5.8.0-31-lowlatency, linux-image-5.8.0-1011-kvm, linux-image-5.8.0-1008-raspi, linux-image-generic-64k, linux-image-virtual, linux-image-5.8.0-1013-azure, linux-image-azure, linux-image-gke, linux-image-aws, linux-image-raspi-nolpae, linux-azure, linux-image-5.8.0-1011-oracle, linux-aws, linux-image-5.8.0-31-generic-64k, linux-image-lowlatency, linux-image-5.8.0-1012-gcp, linux-image-5.8.0-1014-aws, linux-image-generic-lpae, linux-image-kvm, linux-image-5.8.0-31-generic, linux-oracle, linux-raspi, linux-image-oem-20.04, linux, linux-image-raspi, linux-kvm, linux-image-gcp, linux-image-5.8.0-1008-raspi-nolpae, linux-image-oracle, linux-image-generic, linux-image-5.8.0-31-generic-lpae
  • USN-4683-1: linux-image-oem-20.04, linux-image-5.6.0-1039-oem, linux-oem-5.6
  • USN-4660-1: linux-image-powerpc64-smp, linux-gcp, linux-image-oracle-lts-18.04, linux-image-aws-hwe, linux-image-virtual, linux-aws-hwe, linux-image-4.15.0-126-generic, linux-gcp-4.15, linux-image-azure, linux-azure-4.15, linux-image-gke, linux-snapdragon, linux-image-4.15.0-1088-aws, linux-image-4.15.0-1088-gcp, linux-image-4.15.0-1091-snapdragon, linux-image-4.15.0-126-lowlatency, linux-azure, linux-image-gcp-lts-18.04, linux-raspi2, linux-hwe, linux-aws, linux-gke-4.15, linux-image-lowlatency, linux-image-snapdragon, linux-image-4.15.0-1074-gke, linux-image-4.15.0-1100-azure, linux-image-powerpc-e500mc, linux-image-powerpc64-emb, linux-image-generic-lpae, linux-image-4.15.0-1103-oem, linux-image-kvm, linux-image-raspi2, linux-oracle, linux-oem, linux-image-4.15.0-1079-kvm, linux-image-4.15.0-1074-raspi2, linux, linux-image-4.15.0-1059-oracle, linux-image-azure-lts-18.04, linux-image-generic-hwe-16.04, linux-image-aws-lts-18.04, linux-image-generic-lpae-hwe-16.04, linux-image-lowlatency-hwe-16.04, linux-image-4.15.0-126-generic-lpae, linux-image-powerpc-smp, linux-image-virtual-hwe-16.04, linux-image-gcp, linux-kvm, linux-image-azure-edge, linux-image-oracle, linux-image-gke-4.15, linux-image-oem, linux-image-generic
  • USN-4658-1: linux-gcp, linux-image-5.4.0-1030-gcp, linux-hwe-5.4, linux-raspi-5.4, linux-image-generic-lpae-hwe-20.04, linux-image-lowlatency-hwe-20.04, linux-image-virtual-hwe-20.04, linux-image-virtual, linux-image-virtual-hwe-18.04, linux-image-azure, linux-image-gke, linux-image-aws, linux-azure, linux-aws, linux-image-5.4.0-1028-kvm, linux-gcp-5.4, linux-image-lowlatency, linux-image-raspi-hwe-18.04, linux-image-generic-lpae, linux-image-kvm, linux-image-generic-hwe-18.04, linux-image-raspi2, linux-image-oem-osp1, linux-oracle, linux-raspi, linux-image-5.4.0-1030-aws, linux-oracle-5.4, linux, linux-image-generic-lpae-hwe-18.04, linux-image-generic-hwe-20.04, linux-image-5.4.0-56-generic-lpae, linux-image-raspi, linux-azure-5.4, linux-kvm, linux-image-5.4.0-1023-raspi, linux-image-5.4.0-1030-oracle, linux-image-gcp, linux-image-lowlatency-hwe-18.04, linux-image-snapdragon-hwe-18.04, linux-image-oracle, linux-image-5.4.0-56-generic, linux-image-oem, linux-image-5.4.0-1032-azure, linux-aws-5.4, linux-image-5.4.0-56-lowlatency, linux-image-generic