A Linux kernel security update has been released for Ubuntu 14.04 ESM, 16.04 LTS, and 18.04 LTS.

USN-4578-1: Linux kernel vulnerabilities

=========================================================================
Ubuntu Security Notice USN-4578-1
October 14, 2020

linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp,
linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem,
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-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-gke-4.15: Linux kernel for Google Container Engine (GKE) systems
- 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 (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:

Hador Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Wen Xu discovered that the XFS file system in the Linux kernel did not
properly validate inode metadata in some situations. An attacker could use
this to construct a malicious XFS image that, when mounted, could cause a
denial of service (system crash). (CVE-2018-10322)

It was discovered that the btrfs file system in the Linux kernel contained
a use-after-free vulnerability when merging free space. An attacker could
use this to construct a malicious btrfs image that, when mounted and
operated on, could cause a denial of service (system crash).
(CVE-2019-19448)

Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)

Giuseppe Scrivano discovered that the overlay file system in the Linux
kernel did not properly perform permission checks in some situations. A
local attacker could possibly use this to bypass intended restrictions and
gain read access to restricted files. (CVE-2020-16120)

It was discovered that the NFS client implementation in the Linux kernel
did not properly perform bounds checking before copying security labels in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2020-25212)

It was discovered that the NFC implementation in the Linux kernel did not
properly perform permissions checks when opening raw sockets. A local
attacker could use this to create or listen to NFC traffic.
(CVE-2020-26088)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1057-oracle 4.15.0-1057.62
linux-image-4.15.0-1072-gke 4.15.0-1072.76
linux-image-4.15.0-1073-raspi2 4.15.0-1073.78
linux-image-4.15.0-1077-kvm 4.15.0-1077.79
linux-image-4.15.0-1086-aws 4.15.0-1086.91
linux-image-4.15.0-1086-gcp 4.15.0-1086.98
linux-image-4.15.0-1089-snapdragon 4.15.0-1089.98
linux-image-4.15.0-1099-azure 4.15.0-1099.110
linux-image-4.15.0-1099-oem 4.15.0-1099.109
linux-image-4.15.0-121-generic 4.15.0-121.123
linux-image-4.15.0-121-generic-lpae 4.15.0-121.123
linux-image-4.15.0-121-lowlatency 4.15.0-121.123
linux-image-aws-lts-18.04 4.15.0.1086.88
linux-image-azure-lts-18.04 4.15.0.1099.72
linux-image-gcp-lts-18.04 4.15.0.1086.104
linux-image-generic 4.15.0.121.108
linux-image-generic-lpae 4.15.0.121.108
linux-image-gke 4.15.0.1072.76
linux-image-gke-4.15 4.15.0.1072.76
linux-image-kvm 4.15.0.1077.73
linux-image-lowlatency 4.15.0.121.108
linux-image-oem 4.15.0.1099.103
linux-image-oracle-lts-18.04 4.15.0.1057.67
linux-image-powerpc-e500mc 4.15.0.121.108
linux-image-powerpc-smp 4.15.0.121.108
linux-image-powerpc64-emb 4.15.0.121.108
linux-image-powerpc64-smp 4.15.0.121.108
linux-image-raspi2 4.15.0.1073.70
linux-image-snapdragon 4.15.0.1089.92
linux-image-virtual 4.15.0.121.108

Ubuntu 16.04 LTS:
linux-image-4.15.0-1056-oracle 4.15.0-1056.61~16.04.1
linux-image-4.15.0-1085-aws 4.15.0-1085.90~16.04.1
linux-image-4.15.0-1086-gcp 4.15.0-1086.98~16.04.1
linux-image-4.15.0-1098-azure 4.15.0-1098.109~16.04.1
linux-image-4.15.0-120-generic 4.15.0-120.122~16.04.1
linux-image-4.15.0-120-generic-lpae 4.15.0-120.122~16.04.1
linux-image-4.15.0-120-lowlatency 4.15.0-120.122~16.04.1
linux-image-aws-hwe 4.15.0.1085.81
linux-image-azure 4.15.0.1098.92
linux-image-gcp 4.15.0.1086.87
linux-image-generic-hwe-16.04 4.15.0.120.121
linux-image-generic-lpae-hwe-16.04 4.15.0.120.121
linux-image-gke 4.15.0.1086.87
linux-image-lowlatency-hwe-16.04 4.15.0.120.121
linux-image-oem 4.15.0.120.121
linux-image-oracle 4.15.0.1056.46
linux-image-virtual-hwe-16.04 4.15.0.120.121

Ubuntu 14.04 ESM:
linux-image-4.15.0-1098-azure 4.15.0-1098.109~14.04.1
linux-image-azure 4.15.0.1098.74

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/4578-1
CVE-2018-10322, CVE-2019-19448, CVE-2020-14314, CVE-2020-16119,
CVE-2020-16120, CVE-2020-25212, CVE-2020-26088

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.15.0-121.123
  https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1086.91
  https://launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1099.110
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1086.98
  https://launchpad.net/ubuntu/+source/linux-gke-4.15/4.15.0-1072.76
  https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1077.79
  https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1099.109
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1057.62
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1073.78
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1089.98
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1085.90~16.04.1
  https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1098.109~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1086.98~16.04.1
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-120.122~16.04.1
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1056.61~16.04.1