USN-4427-1: Linux kernel vulnerabilities

27 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-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
  • linux-raspi2 - Linux kernel for Raspberry Pi (V7) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

It was discovered that the Kvaser CAN/USB driver in the Linux kernel did
not properly initialize memory in certain situations. A local attacker
could possibly use this to expose sensitive information (kernel memory).
(CVE-2019-19947)

Chuhong Yuan discovered that go7007 USB audio device driver in the Linux
kernel did not properly deallocate memory in some failure conditions. A
physically proximate attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2019-20810)

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)

It was discovered that the elf handling code in the Linux kernel did not
initialize memory before using it in certain situations. A local attacker
could use this to possibly expose sensitive information (kernel memory).
(CVE-2020-10732)

It was discovered that the Linux kernel did not correctly apply Speculative
Store Bypass Disable (SSBD) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10766)

It was discovered that the Linux kernel did not correctly apply Indirect
Branch Predictor Barrier (IBPB) mitigations in certain situations. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-10767)

It was discovered that the Linux kernel could incorrectly enable Indirect
Branch Speculation after it has been disabled for a process via a prctl()
call. A local attacker could possibly use this to expose sensitive
information. (CVE-2020-10768)

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)

It was discovered that the Virtual Terminal keyboard driver in the Linux
kernel contained an integer overflow. A local attacker could possibly use
this to have an unspecified impact. (CVE-2020-13974)

It was discovered that the efi subsystem in the Linux kernel did not handle
memory allocation failures during early boot in some situations. A local
attacker could possibly use this to cause a denial of service (system
crash). (CVE-2019-12380)

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-4439-1: linux-image-5.0.0-1045-gke, linux-image-5.0.0-1065-oem-osp1, linux-gke-5.0, linux-image-gke-5.0, linux-oem-osp1, linux-image-oem-osp1
  • USN-4425-1: linux-azure-5.4, linux-image-lowlatency, linux-raspi, linux-image-snapdragon-hwe-18.04, linux-riscv, linux-image-5.4.0-42-lowlatency, linux-image-gke, linux-image-virtual, linux-image-azure, linux-image-aws, linux-image-5.4.0-1015-raspi, linux-image-generic-lpae, linux-image-generic-lpae-hwe-18.04, linux-image-oem, linux-kvm, linux-raspi-5.4, linux-image-5.4.0-1022-azure, linux, linux-aws, linux-image-raspi, linux-image-5.4.0-30-generic, linux-image-azure-edge, linux-hwe-5.4, linux-image-generic, linux-image-kvm, linux-image-oracle, linux-image-lowlatency-hwe-18.04, linux-image-virtual-hwe-18.04, linux-image-raspi2, linux-image-raspi-hwe-18.04, linux-image-5.4.0-1021-oracle, linux-image-generic-hwe-18.04, linux-azure, linux-image-5.4.0-1020-aws, linux-image-oem-osp1, linux-image-gkeop-5.4, linux-image-5.4.0-42-generic, linux-image-5.4.0-1021-gcp, linux-gcp, linux-image-5.4.0-42-generic-lpae, linux-oracle, linux-image-gcp
  • USN-4411-1: linux-image-5.4.0-40-lowlatency, linux-image-lowlatency, linux-raspi, linux-riscv, linux-image-5.4.0-1019-oracle, linux-image-gke, linux-image-virtual, linux-image-5.4.0-28-generic, linux-image-azure, linux-image-aws, linux-image-generic-lpae, linux-image-oem, linux-kvm, linux-image-5.4.0-1013-raspi, linux, linux-aws, linux-image-raspi, linux-image-generic, linux-image-kvm, linux-image-oracle, linux-image-raspi2, linux-image-5.4.0-1019-gcp, linux-azure, linux-image-5.4.0-40-generic, linux-image-oem-osp1, linux-image-5.4.0-40-generic-lpae, linux-image-5.4.0-1020-azure, linux-gcp, linux-image-5.4.0-1018-aws, linux-oracle, linux-image-gcp
  • USN-4285-1: linux-aws-5.0, linux-image-5.0.0-1025-aws, linux-image-5.0.0-1031-gcp, linux-image-5.0.0-1032-azure, linux-image-5.0.0-1011-oracle, linux-image-gke-5.0, linux-gke-5.0, linux-gcp, linux-azure, linux-image-5.0.0-1030-gke, linux-image-azure, linux-oracle-5.0, linux-image-gcp
  • USN-4284-1: linux-image-5.3.0-1018-raspi2, linux-image-lowlatency, linux-image-snapdragon-hwe-18.04, linux-image-gke, linux-image-virtual, linux-image-snapdragon, linux-image-raspi2-hwe-18.04, linux-gcp-5.3, linux-image-azure, linux-image-aws, linux-image-gcp-edge, linux-image-5.3.0-1009-oracle, linux-image-generic-lpae, linux-image-generic-lpae-hwe-18.04, linux-kvm, linux-raspi2-5.3, linux-azure-5.3, linux, linux-aws, linux-image-5.3.0-40-lowlatency, linux-image-azure-edge, linux-image-5.3.0-1012-gcp, linux-image-generic, linux-image-kvm, linux-image-5.3.0-1013-azure, linux-image-oracle, linux-image-lowlatency-hwe-18.04, linux-image-virtual-hwe-18.04, linux-image-raspi2, linux-image-5.3.0-1010-kvm, linux-image-5.3.0-40-snapdragon, linux-hwe, linux-raspi2, linux-image-5.3.0-40-generic-lpae, linux-image-generic-hwe-18.04, linux-azure, linux-image-5.3.0-40-generic, linux-image-5.3.0-1011-aws, linux-gcp, linux-oracle, linux-image-gcp
  • USN-4485-1: linux-image-4.15.0-1067-gke, linux-image-lowlatency, linux-image-gke, linux-image-virtual, linux-image-snapdragon, linux-image-azure, linux-image-generic-lpae, linux-image-virtual-hwe-16.04, linux-image-4.15.0-1072-kvm, linux-image-4.15.0-1068-raspi2, linux-aws-hwe, linux-image-azure-lts-18.04, linux-image-oem, linux-kvm, linux-image-4.15.0-1081-gcp, linux, linux-image-aws-hwe, linux-snapdragon, linux-image-4.15.0-1080-aws, linux-image-4.15.0-1094-oem, linux-aws, linux-image-oracle-lts-18.04, linux-image-azure-edge, linux-image-powerpc64-emb, linux-image-4.15.0-1051-oracle, linux-image-generic, linux-image-kvm, linux-image-oracle, linux-image-gke-4.15, linux-image-raspi2, linux-image-4.15.0-115-generic-lpae, linux-image-lowlatency-hwe-16.04, linux-image-4.15.0-115-generic, linux-raspi2, linux-hwe, linux-image-generic-lpae-hwe-16.04, linux-azure-4.15, linux-azure, linux-image-aws-lts-18.04, linux-image-powerpc-e500mc, linux-image-4.15.0-1084-snapdragon, linux-image-powerpc64-smp, linux-oem, linux-image-4.15.0-115-lowlatency, linux-gke-4.15, linux-image-4.15.0-1093-azure, linux-image-gcp-lts-18.04, linux-gcp, linux-image-generic-hwe-16.04, linux-image-powerpc-smp, linux-gcp-4.15, linux-oracle, linux-image-gcp
  • USN-4414-1: linux-image-4.15.0-1046-oracle, linux-image-4.15.0-109-generic, linux-image-lowlatency, linux-image-4.15.0-1078-gcp, linux-image-4.15.0-107-generic-lpae, linux-image-4.15.0-1074-aws, linux-image-gke, linux-image-virtual, linux-image-snapdragon, linux-image-4.15.0-1048-oracle, linux-image-azure, linux-image-generic-lpae, linux-image-4.15.0-109-generic-lpae, linux-image-virtual-hwe-16.04, linux-aws-hwe, linux-image-azure-lts-18.04, linux-image-oem, linux-image-4.15.0-109-lowlatency, linux-kvm, linux-snapdragon, linux-image-4.15.0-107-lowlatency, linux, linux-image-aws-hwe, linux-aws, linux-image-oracle-lts-18.04, linux-image-powerpc64-emb, linux-image-generic, linux-image-kvm, linux-image-4.15.0-107-generic, linux-image-oracle, linux-image-4.15.0-1091-azure, linux-image-gke-4.15, linux-image-raspi2, linux-image-4.15.0-1069-kvm, linux-image-4.15.0-1077-aws, linux-image-lowlatency-hwe-16.04, linux-raspi2, linux-hwe, linux-image-generic-lpae-hwe-16.04, linux-image-4.15.0-1064-gke, linux-azure-4.15, linux-azure, linux-image-4.15.0-1081-snapdragon, linux-image-aws-lts-18.04, linux-image-powerpc-e500mc, linux-image-powerpc64-smp, linux-oem, linux-gke-4.15, linux-image-4.15.0-1065-raspi2, linux-image-gcp-lts-18.04, linux-gcp, linux-image-generic-hwe-16.04, linux-image-powerpc-smp, linux-image-4.15.0-1091-oem, linux-gcp-4.15, linux-oracle, linux-image-gcp
  • USN-4483-1: linux-azure-5.4, linux-image-lowlatency, linux-raspi, linux-image-snapdragon-hwe-18.04, linux-image-gke, linux-image-virtual, linux-image-azure, linux-aws-5.4, linux-image-aws, linux-image-generic-lpae, linux-image-generic-lpae-hwe-18.04, linux-oracle-5.4, linux-image-oem, linux-kvm, linux-raspi-5.4, linux, linux-aws, linux-image-raspi, linux-image-aws-edge, linux-hwe-5.4, linux-image-generic, linux-image-gke-5.4, linux-image-kvm, linux-image-5.4.0-1016-raspi, linux-image-5.4.0-1022-gcp, linux-image-lowlatency-hwe-18.04, linux-image-oracle, linux-image-raspi2, linux-image-virtual-hwe-18.04, linux-image-raspi-hwe-18.04, linux-gcp-5.4, linux-image-5.4.0-1022-aws, linux-image-generic-hwe-18.04, linux-azure, linux-image-oem-osp1, linux-image-gkeop-5.4, linux-image-5.4.0-45-generic-lpae, linux-image-5.4.0-1022-oracle, linux-image-5.4.0-45-lowlatency, linux-gcp, linux-image-5.4.0-1023-azure, linux-image-5.4.0-45-generic, linux-oracle, linux-image-gcp
  • USN-4440-1: linux-image-5.3.0-1030-oracle, linux-aws-5.3, linux-image-5.3.0-1032-aws, linux-image-raspi2-hwe-18.04, linux-gcp-5.3, linux-image-azure, linux-image-aws, linux-image-5.3.0-1032-gcp, linux-image-gkeop-5.3, linux-raspi2-5.3, linux-azure-5.3, linux-image-gke-5.3, linux-image-5.3.0-1030-raspi2, linux-image-oracle, linux-image-5.3.0-64-generic, linux-gke-5.3, linux-oracle-5.3, linux-hwe, linux-image-5.3.0-64-generic-lpae, linux-image-5.3.0-64-lowlatency, linux-image-5.3.0-1034-azure, linux-image-5.3.0-1032-gke, linux-image-gcp
  • USN-4426-1: linux-image-lowlatency, linux-image-4.15.0-1066-gke, linux-image-gke, linux-image-virtual, linux-image-snapdragon, linux-image-azure, linux-image-generic-lpae, linux-image-virtual-hwe-16.04, linux-aws-hwe, linux-image-azure-lts-18.04, linux-image-oem, linux-kvm, linux-snapdragon, linux-image-aws-hwe, linux, linux-image-4.15.0-1093-oem, linux-image-4.15.0-112-generic, linux-aws, linux-image-4.15.0-112-generic-lpae, linux-image-oracle-lts-18.04, linux-image-4.15.0-1092-azure, linux-image-powerpc64-emb, linux-image-generic, linux-image-kvm, linux-image-oracle, linux-image-gke-4.15, linux-image-raspi2, linux-image-4.15.0-1050-oracle, linux-image-lowlatency-hwe-16.04, linux-image-4.15.0-112-lowlatency, linux-image-4.15.0-1080-gcp, linux-raspi2, linux-hwe, linux-image-generic-lpae-hwe-16.04, linux-azure-4.15, linux-gcp-4.15, linux-azure, linux-image-4.15.0-1083-snapdragon, linux-image-4.15.0-1067-raspi2, linux-image-4.15.0-1071-kvm, linux-image-aws-lts-18.04, linux-image-powerpc-e500mc, linux-image-powerpc64-smp, linux-oem, linux-gke-4.15, linux-image-gcp-lts-18.04, linux-gcp, linux-image-generic-hwe-16.04, linux-image-powerpc-smp, linux-image-4.15.0-1079-aws, linux-oracle, linux-image-gcp