A Linux kernel security update has been released for both Ubuntu Linux 18.04 LTS and 16.04 LTS.

=========================================================================
Ubuntu Security Notice USN-4302-1
March 17, 2020

linux, linux-aws, linux-aws-hwe, linux-gcp, linux-gke-4.15, linux-hwe,
linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-gke-4.15: Linux kernel for Google Container Engine (GKE) systems
- linux-kvm: Linux kernel for cloud environments
- linux-raspi2: Linux kernel for Raspberry Pi 2
- linux-snapdragon: Linux kernel for Snapdragon processors
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

Paulo Bonzini discovered that the KVM hypervisor implementation in the
Linux kernel could improperly let a nested (level 2) guest access the
resources of a parent (level 1) guest in certain situations. An attacker
could use this to expose sensitive information. (CVE-2020-2732)

Gregory Herrero discovered that the fix for CVE-2019-14615 to address the
Linux kernel not properly clearing data structures on context switches for
certain Intel graphics processors was incomplete. A local attacker could
use this to expose sensitive information. (CVE-2020-8832)

It was discovered that the IPMI message handler implementation in the Linux
kernel did not properly deallocate memory in certain situations. A local
attacker could use this to cause a denial of service (kernel memory
exhaustion). (CVE-2019-19046)

It was discovered that the Intel WiMAX 2400 driver in the Linux kernel did
not properly deallocate memory in certain situations. A local attacker
could use this to cause a denial of service (kernel memory exhaustion).
(CVE-2019-19051)

It was discovered that the Marvell Wi-Fi device driver in the Linux kernel
did not properly deallocate memory in certain error conditions. A local
attacker could use this to possibly cause a denial of service (kernel
memory exhaustion). (CVE-2019-19056)

It was discovered that the Intel(R) Wi-Fi device driver in the Linux kernel
device driver in the Linux kernel did not properly deallocate memory in
certain error conditions. A local attacker could possibly use this to cause
a denial of service (kernel memory exhaustion). (CVE-2019-19058)

It was discovered that the Brocade BFA Fibre Channel device driver in the
Linux kernel did not properly deallocate memory in certain error
conditions. A local attacker could possibly use this to cause a denial of
service (kernel memory exhaustion). (CVE-2019-19066)

It was discovered that the Realtek RTL8xxx USB Wi-Fi device driver in the
Linux kernel did not properly deallocate memory in certain error
conditions. A local attacker could possibly use this to cause a denial of
service (kernel memory exhaustion). (CVE-2019-19068)

It was discovered that ZR364XX Camera USB device driver for the Linux
kernel did not properly initialize memory. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-15217)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1055-gke 4.15.0-1055.58
linux-image-4.15.0-1056-kvm 4.15.0-1056.57
linux-image-4.15.0-1057-raspi2 4.15.0-1057.61
linux-image-4.15.0-1063-aws 4.15.0-1063.67
linux-image-4.15.0-1074-snapdragon 4.15.0-1074.81
linux-image-4.15.0-91-generic 4.15.0-91.92
linux-image-4.15.0-91-generic-lpae 4.15.0-91.92
linux-image-4.15.0-91-lowlatency 4.15.0-91.92
linux-image-aws 4.15.0.1063.64
linux-image-aws-lts-18.04 4.15.0.1063.64
linux-image-generic 4.15.0.91.83
linux-image-generic-lpae 4.15.0.91.83
linux-image-gke 4.15.0.1055.59
linux-image-gke-4.15 4.15.0.1055.59
linux-image-kvm 4.15.0.1056.56
linux-image-lowlatency 4.15.0.91.83
linux-image-powerpc-e500mc 4.15.0.91.83
linux-image-powerpc-smp 4.15.0.91.83
linux-image-powerpc64-emb 4.15.0.91.83
linux-image-powerpc64-smp 4.15.0.91.83
linux-image-raspi2 4.15.0.1057.55
linux-image-snapdragon 4.15.0.1074.77
linux-image-virtual 4.15.0.91.83

Ubuntu 16.04 LTS:
linux-image-4.15.0-1058-gcp 4.15.0-1058.62
linux-image-4.15.0-1063-aws 4.15.0-1063.67~16.04.1
linux-image-4.15.0-91-generic 4.15.0-91.92~16.04.1
linux-image-4.15.0-91-generic-lpae 4.15.0-91.92~16.04.1
linux-image-4.15.0-91-lowlatency 4.15.0-91.92~16.04.1
linux-image-aws-hwe 4.15.0.1063.63
linux-image-gcp 4.15.0.1058.72
linux-image-generic-hwe-16.04 4.15.0.91.101
linux-image-generic-lpae-hwe-16.04 4.15.0.91.101
linux-image-gke 4.15.0.1058.72
linux-image-lowlatency-hwe-16.04 4.15.0.91.101
linux-image-oem 4.15.0.91.101
linux-image-virtual-hwe-16.04 4.15.0.91.101

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:
  https://usn.ubuntu.com/4302-1
CVE-2019-15217, CVE-2019-19046, CVE-2019-19051, CVE-2019-19056,
CVE-2019-19058, CVE-2019-19066, CVE-2019-19068, CVE-2020-2732,
CVE-2020-8832

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.15.0-91.92
  https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1063.67
  https://launchpad.net/ubuntu/+source/linux-gke-4.15/4.15.0-1055.58
  https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1056.57
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1057.61
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1074.81
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1063.67~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1058.62
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-91.92~16.04.1