USN-4363-1: Linux kernel vulnerabilities

Releases

• Ubuntu 18.04 ESM
• Ubuntu 16.04 ESM

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-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

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

• linux-image-4.15.0-101-generic - 4.15.0-101.102
• linux-image-4.15.0-101-generic-lpae - 4.15.0-101.102
• linux-image-4.15.0-101-lowlatency - 4.15.0-101.102
• linux-image-4.15.0-1039-oracle - 4.15.0-1039.43
• linux-image-4.15.0-1059-gke - 4.15.0-1059.62
• linux-image-4.15.0-1060-kvm - 4.15.0-1060.61
• linux-image-4.15.0-1062-raspi2 - 4.15.0-1062.66
• linux-image-4.15.0-1067-aws - 4.15.0-1067.71
• linux-image-4.15.0-1079-snapdragon - 4.15.0-1079.86
• linux-image-4.15.0-1081-oem - 4.15.0-1081.91
• linux-image-4.15.0-1083-azure - 4.15.0-1083.93
• linux-image-aws-lts-18.04 - 4.15.0.1067.70
• linux-image-azure-lts-18.04 - 4.15.0.1083.54
• linux-image-generic - 4.15.0.101.91
• linux-image-generic-lpae - 4.15.0.101.91
• linux-image-gke - 4.15.0.1059.63
• linux-image-gke-4.15 - 4.15.0.1059.63
• linux-image-kvm - 4.15.0.1060.60
• linux-image-lowlatency - 4.15.0.101.91
• linux-image-oem - 4.15.0.1081.85
• linux-image-oracle-lts-18.04 - 4.15.0.1039.48
• linux-image-raspi2 - 4.15.0.1062.60
• linux-image-snapdragon - 4.15.0.1079.82
• linux-image-virtual - 4.15.0.101.91

Ubuntu 16.04

• linux-image-4.15.0-101-generic - 4.15.0-101.102~16.04.1
• linux-image-4.15.0-101-generic-lpae - 4.15.0-101.102~16.04.1
• linux-image-4.15.0-101-lowlatency - 4.15.0-101.102~16.04.1
• linux-image-4.15.0-1039-oracle - 4.15.0-1039.43~16.04.1
• linux-image-4.15.0-1067-aws - 4.15.0-1067.71~16.04.1
• linux-image-4.15.0-1071-gcp - 4.15.0-1071.81~16.04.1
• linux-image-4.15.0-1083-azure - 4.15.0-1083.93~16.04.1
• linux-image-aws-hwe - 4.15.0.1067.67
• linux-image-azure - 4.15.0.1083.82
• linux-image-azure-edge - 4.15.0.1083.82
• linux-image-gcp - 4.15.0.1071.77
• linux-image-generic-hwe-16.04 - 4.15.0.101.108
• linux-image-generic-lpae-hwe-16.04 - 4.15.0.101.108
• linux-image-gke - 4.15.0.1071.77
• linux-image-lowlatency-hwe-16.04 - 4.15.0.101.108
• linux-image-oem - 4.15.0.101.108
• linux-image-oracle - 4.15.0.1039.32
• linux-image-virtual-hwe-16.04 - 4.15.0.101.108

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.

References

• CVE-2020-11494
• CVE-2020-11565
• CVE-2020-11669
• CVE-2020-12657

Related notices

• USN-4369-1: linux-image-azure-edge, linux-image-generic-lpae-hwe-18.04, linux-image-kvm, linux-image-snapdragon-hwe-18.04-edge, linux-image-oracle-edge, linux-aws, linux-image-5.3.0-1020-gke, linux-image-aws, linux-image-virtual, linux-image-azure, linux-image-gcp, linux-image-generic-lpae-hwe-18.04-edge, linux-image-5.3.0-1019-aws, linux-image-gkeop-5.3, linux-image-gke-5.3, linux-oracle, linux-oracle-5.3, linux-image-lowlatency-hwe-18.04-edge, linux-hwe, linux-image-5.3.0-1022-azure, linux-image-5.3.0-53-generic-lpae, linux-image-gcp-edge, linux-image-gke, linux-kvm, linux-image-lowlatency, linux-image-5.3.0-53-lowlatency, linux-raspi2, linux, linux-image-5.3.0-1020-gcp, linux-gcp, linux-image-raspi2, linux-image-snapdragon, linux-gke-5.3, linux-image-generic-hwe-18.04, linux-image-generic-lpae, linux-image-5.3.0-1017-kvm, linux-image-lowlatency-hwe-18.04, linux-image-generic-hwe-18.04-edge, linux-image-5.3.0-1018-oracle, linux-image-5.3.0-53-generic, linux-image-5.3.0-1025-raspi2, linux-gcp-5.3, linux-image-aws-edge, linux-azure-5.3, linux-image-generic, linux-image-oracle, linux-image-snapdragon-hwe-18.04, linux-image-virtual-hwe-18.04, linux-aws-5.3, linux-image-5.3.0-53-snapdragon, linux-azure, linux-image-virtual-hwe-18.04-edge
• USN-4364-1: linux-image-kvm, linux-image-4.4.0-179-powerpc-smp, linux-aws, linux-image-lowlatency-lts-vivid, linux-image-aws, linux-image-generic-lts-vivid, linux-image-powerpc-smp, linux-image-virtual, linux-image-powerpc64-emb-lts-wily, linux-image-virtual-lts-utopic, linux-image-powerpc-e500mc-lts-xenial, linux-image-powerpc64-emb-lts-utopic, linux-image-powerpc-smp-lts-wily, linux-image-generic-lpae-lts-wily, linux-image-4.4.0-1107-aws, linux-image-lowlatency-lts-wily, linux-image-generic-lpae-lts-utopic, linux-image-powerpc64-smp-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-kvm, linux-image-powerpc64-smp-lts-vivid, linux-image-lowlatency, linux-image-lowlatency-lts-utopic, linux-image-powerpc-smp-lts-xenial, linux-image-generic-lts-xenial, linux-image-4.4.0-179-generic-lpae, linux, linux-image-generic-lpae-lts-vivid, linux-image-4.4.0-1133-raspi2, linux-image-powerpc-e500mc-lts-utopic, linux-image-powerpc-smp-lts-vivid, linux-image-raspi2, linux-image-4.4.0-179-lowlatency, linux-image-powerpc-e500mc-lts-wily, linux-image-snapdragon, linux-lts-xenial, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc-smp-lts-utopic, linux-image-generic-lpae, linux-image-4.4.0-179-powerpc-e500mc, linux-image-generic-lts-utopic, linux-raspi2, linux-image-generic, linux-image-virtual-lts-wily, linux-image-4.4.0-1067-aws, linux-image-powerpc64-emb, linux-image-4.4.0-179-powerpc64-smp, linux-image-virtual-lts-xenial, linux-snapdragon, linux-image-powerpc64-smp-lts-utopic, linux-image-virtual-lts-vivid, linux-image-lowlatency-lts-xenial, linux-image-4.4.0-1137-snapdragon, linux-image-4.4.0-179-generic, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc-e500mc, linux-image-powerpc64-smp, linux-image-4.4.0-1071-kvm, linux-image-powerpc64-emb-lts-xenial, linux-image-4.4.0-179-powerpc64-emb, linux-image-generic-lts-wily, linux-image-generic-lpae-lts-xenial
• USN-4368-1: linux-image-5.0.0-1037-gke, linux-image-oem-osp1, linux-gke-5.0, linux-image-gke-5.0, linux-image-5.0.0-1052-oem-osp1, linux-oem-osp1
• LSN-0067-1: generic-4.4, gcp, lowlatency-4.15, azure, aws, oem, generic-4.15, lowlatency-4.4
• LSN-0068-1: generic-4.4, lowlatency-4.15, aws, oem, generic-4.15, lowlatency-4.4
• LSN-0072-1: generic-4.4, gcp, lowlatency-4.15, azure, aws, lowlatency-5.4, oem, generic-4.15, generic-5.4, lowlatency-4.4
• USN-4367-1: linux-image-generic-lpae-hwe-18.04, linux-image-5.4.0-1011-kvm, linux-image-kvm, linux-aws, linux-image-5.4.0-1011-oracle, linux-image-aws, linux-image-azure, linux-image-5.4.0-1011-gcp, linux-image-5.4.0-26-generic, linux-image-gcp, linux-image-generic-lpae-hwe-18.04-edge, linux-image-virtual, linux-oracle, linux-image-lowlatency-hwe-18.04-edge, linux-image-5.4.0-31-lowlatency, linux-image-oem, linux-image-gke, linux-image-virtual-hwe-20.04, linux-kvm, linux-image-lowlatency, linux-raspi, linux, linux-image-raspi2, linux-gcp, linux-riscv, linux-image-oem-osp1, linux-image-5.4.0-31-generic-lpae, linux-image-generic-hwe-18.04, linux-image-raspi, linux-image-generic-lpae, linux-image-5.4.0-1011-raspi, linux-image-lowlatency-hwe-18.04, linux-image-5.4.0-1012-azure, linux-image-generic-hwe-18.04-edge, linux-image-generic-hwe-20.04, linux-image-lowlatency-hwe-20.04, linux-image-generic, linux-image-virtual-hwe-18.04, linux-image-5.4.0-1011-aws, linux-image-generic-lpae-hwe-20.04, linux-image-oracle, linux-azure, linux-image-5.4.0-31-generic, linux-image-virtual-hwe-18.04-edge