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

USN-4414-1: Linux kernel vulnerabilities

=========================================================================
Ubuntu Security Notice USN-4414-1
July 03, 2020

linux, linux-aws, linux-aws-hwe, 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

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-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 (V7) systems
- linux-snapdragon: Linux kernel for Qualcomm 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:

It was discovered that the network block device (nbd) implementation in the
Linux kernel did not properly check for error conditions in some
situations. An attacker could possibly use this to cause a denial of service
(system crash). (CVE-2019-16089)

It was discovered that the btrfs file system implementation in the Linux
kernel did not properly validate file system metadata in some situations.
An attacker could use this to construct a malicious btrfs image that, when
mounted, could cause a denial of service (system crash). (CVE-2019-19036,
CVE-2019-19318, CVE-2019-19813, CVE-2019-19816)

It was discovered that the btrfs implementation in the Linux kernel did not
properly detect that a block was marked dirty in some situations. An
attacker could use this to specially craft a file system image that, when
unmounted, could cause a denial of service (system crash). (CVE-2019-19377)

It was discovered that the kernel->user space relay implementation in the
Linux kernel did not properly check return values in some situations. A
local attacker could possibly use this to cause a denial of service (system
crash). (CVE-2019-19462)

Matthew Sheets discovered that the SELinux network label handling
implementation in the Linux kernel could be coerced into de-referencing a
NULL pointer. A remote attacker could use this to cause a denial of service
(system crash). (CVE-2020-10711)

It was discovered that the SCSI generic (sg) driver in the Linux kernel did
not properly handle certain error conditions correctly. A local privileged
attacker could use this to cause a denial of service (system crash).
(CVE-2020-12770)

It was discovered that the USB Gadget device driver in the Linux kernel did
not validate arguments passed from configfs in some situations. A local
attacker could possibly use this to cause a denial of service (system
crash) or possibly expose sensitive information. (CVE-2020-13143)

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)

It was discovered that the btrfs file system in the Linux kernel in some
error conditions could report register information to the dmesg buffer. A
local attacker could possibly use this to expose sensitive information.
(CVE-2019-19039)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1048-oracle 4.15.0-1048.52
linux-image-4.15.0-1064-gke 4.15.0-1064.67
linux-image-4.15.0-1065-raspi2 4.15.0-1065.69
linux-image-4.15.0-1069-kvm 4.15.0-1069.70
linux-image-4.15.0-1077-aws 4.15.0-1077.81
linux-image-4.15.0-1078-gcp 4.15.0-1078.88
linux-image-4.15.0-1081-snapdragon 4.15.0-1081.88
linux-image-4.15.0-109-generic 4.15.0-109.110
linux-image-4.15.0-109-generic-lpae 4.15.0-109.110
linux-image-4.15.0-109-lowlatency 4.15.0-109.110
linux-image-4.15.0-1091-oem 4.15.0-1091.101
linux-image-aws-lts-18.04 4.15.0.1077.79
linux-image-gcp-lts-18.04 4.15.0.1078.94
linux-image-generic 4.15.0.109.97
linux-image-generic-lpae 4.15.0.109.97
linux-image-gke 4.15.0.1064.66
linux-image-gke-4.15 4.15.0.1064.66
linux-image-kvm 4.15.0.1069.65
linux-image-lowlatency 4.15.0.109.97
linux-image-oem 4.15.0.1091.94
linux-image-oracle-lts-18.04 4.15.0.1048.57
linux-image-powerpc-e500mc 4.15.0.109.97
linux-image-powerpc-smp 4.15.0.109.97
linux-image-powerpc64-emb 4.15.0.109.97
linux-image-powerpc64-smp 4.15.0.109.97
linux-image-raspi2 4.15.0.1065.63
linux-image-snapdragon 4.15.0.1081.84
linux-image-virtual 4.15.0.109.97

Ubuntu 16.04 LTS:
linux-image-4.15.0-1046-oracle 4.15.0-1046.50~16.04.1
linux-image-4.15.0-107-generic 4.15.0-107.108~16.04.1
linux-image-4.15.0-107-generic-lpae 4.15.0-107.108~16.04.1
linux-image-4.15.0-107-lowlatency 4.15.0-107.108~16.04.1
linux-image-4.15.0-1074-aws 4.15.0-1074.78~16.04.1
linux-image-4.15.0-1078-gcp 4.15.0-1078.88~16.04.1
linux-image-aws-hwe 4.15.0.1074.74
linux-image-gcp 4.15.0.1078.80
linux-image-generic-hwe-16.04 4.15.0.107.112
linux-image-generic-lpae-hwe-16.04 4.15.0.107.112
linux-image-gke 4.15.0.1078.80
linux-image-lowlatency-hwe-16.04 4.15.0.107.112
linux-image-oem 4.15.0.107.112
linux-image-oracle 4.15.0.1046.39
linux-image-virtual-hwe-16.04 4.15.0.107.112

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/4414-1
CVE-2019-12380, CVE-2019-16089, CVE-2019-19036, CVE-2019-19039,
CVE-2019-19318, CVE-2019-19377, CVE-2019-19462, CVE-2019-19813,
CVE-2019-19816, CVE-2020-10711, CVE-2020-12770, CVE-2020-13143

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.15.0-109.110
  https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1077.81
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1078.88
  https://launchpad.net/ubuntu/+source/linux-gke-4.15/4.15.0-1064.67
  https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1069.70
  https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1091.101
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1048.52
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1065.69
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1081.88
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1074.78~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1078.88~16.04.1
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-107.108~16.04.1
  https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1046.50~16.04.1