==========================================================================
Ubuntu Security Notice USN-4877-1
March 16, 2021

linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15,
linux-dell300x, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm,
linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

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-azure-4.15: Linux kernel for Microsoft Azure Cloud systems
- linux-dell300x: Linux kernel for Dell 300x platforms
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-kvm: Linux kernel for cloud environments
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-raspi2: Linux kernel for Raspberry Pi (V8) systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

It was discovered that the Marvell WiFi-Ex device driver in the Linux
kernel did not properly validate ad-hoc SSIDs. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2020-36158)

吴异 discovered that the NFS implementation in the Linux kernel did not
properly prevent access outside of an NFS export that is a subdirectory of
a file system. An attacker could possibly use this to bypass NFS access
restrictions. (CVE-2021-3178)

Update instructions:

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1013-dell300x  4.15.0-1013.17
  linux-image-4.15.0-1066-oracle  4.15.0-1066.74
  linux-image-4.15.0-1080-raspi2  4.15.0-1080.85
  linux-image-4.15.0-1086-kvm     4.15.0-1086.88
  linux-image-4.15.0-1094-gcp     4.15.0-1094.107
  linux-image-4.15.0-1095-aws     4.15.0-1095.102
  linux-image-4.15.0-1097-snapdragon  4.15.0-1097.106
  linux-image-4.15.0-1109-azure   4.15.0-1109.121
  linux-image-4.15.0-137-generic  4.15.0-137.141
  linux-image-4.15.0-137-generic-lpae  4.15.0-137.141
  linux-image-4.15.0-137-lowlatency  4.15.0-137.141
  linux-image-aws-lts-18.04       4.15.0.1095.98
  linux-image-azure-lts-18.04     4.15.0.1109.82
  linux-image-dell300x            4.15.0.1013.15
  linux-image-gcp-lts-18.04       4.15.0.1094.112
  linux-image-generic             4.15.0.137.124
  linux-image-generic-lpae        4.15.0.137.124
  linux-image-kvm                 4.15.0.1086.82
  linux-image-lowlatency          4.15.0.137.124
  linux-image-oracle-lts-18.04    4.15.0.1066.76
  linux-image-powerpc-e500mc      4.15.0.137.124
  linux-image-powerpc-smp         4.15.0.137.124
  linux-image-powerpc64-emb       4.15.0.137.124
  linux-image-powerpc64-smp       4.15.0.137.124
  linux-image-raspi2              4.15.0.1080.77
  linux-image-snapdragon          4.15.0.1097.100
  linux-image-virtual             4.15.0.137.124

Ubuntu 16.04 LTS:
  linux-image-4.15.0-1066-oracle  4.15.0-1066.74~16.04.1
  linux-image-4.15.0-1094-gcp     4.15.0-1094.107~16.04.1
  linux-image-4.15.0-1095-aws     4.15.0-1095.102~16.04.1
  linux-image-4.15.0-1109-azure   4.15.0-1109.121~16.04.1
  linux-image-4.15.0-137-generic  4.15.0-137.141~16.04.1
  linux-image-4.15.0-137-generic-lpae  4.15.0-137.141~16.04.1
  linux-image-4.15.0-137-lowlatency  4.15.0-137.141~16.04.1
  linux-image-aws-hwe             4.15.0.1095.88
  linux-image-azure               4.15.0.1109.100
  linux-image-gcp                 4.15.0.1094.95
  linux-image-generic-hwe-16.04   4.15.0.137.133
  linux-image-generic-lpae-hwe-16.04  4.15.0.137.133
  linux-image-gke                 4.15.0.1094.95
  linux-image-lowlatency-hwe-16.04  4.15.0.137.133
  linux-image-oem                 4.15.0.137.133
  linux-image-oracle              4.15.0.1066.54
  linux-image-virtual-hwe-16.04   4.15.0.137.133

Ubuntu 14.04 ESM:
  linux-image-4.15.0-1109-azure   4.15.0-1109.121~14.04.1
  linux-image-azure               4.15.0.1109.82

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://ubuntu.com/security/notices/USN-4877-1
  CVE-2020-36158, CVE-2021-3178

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.15.0-137.141
  https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1095.102
  https://launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1109.121
  https://launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1013.17
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1094.107
  https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1086.88
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1066.74
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1080.85
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1097.106
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1095.102~16.04.1
  https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1109.121~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1094.107~16.04.1
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-137.141~16.04.1
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1066.74~16.04.1