==========================================================================
Ubuntu Security Notice USN-5727-2
November 18, 2022

linux-gcp, linux-gcp-4.15  vulnerabilities
==========================================================================

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

Details:

It was discovered that a race condition existed in the instruction emulator
of the Linux kernel on Arm 64-bit systems. A local attacker could use this
to cause a denial of service (system crash). (CVE-2022-20422)

It was discovered that the KVM implementation in the Linux kernel did not
properly handle virtual CPUs without APICs in certain situations. A local
attacker could possibly use this to cause a denial of service (host system
crash). (CVE-2022-2153)

Hao Sun and Jiacheng Xu discovered that the NILFS file system
implementation in the Linux kernel contained 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-2022-2978)

Abhishek Shah discovered a race condition in the PF_KEYv2 implementation in
the Linux kernel. A local attacker could use this to cause a denial of
service (system crash) or possibly expose sensitive information (kernel
memory). (CVE-2022-3028)

It was discovered that the IDT 77252 ATM PCI device driver in the Linux
kernel did not properly remove any pending timers during device exit,
resulting in 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-2022-3635)

It was discovered that the Netlink Transformation (XFRM) subsystem in the
Linux kernel contained a reference counting error. A local attacker could
use this to cause a denial of service (system crash). (CVE-2022-36879)

Xingyuan Mo and Gengjia Chen discovered that the Promise SuperTrak EX
storage controller driver in the Linux kernel did not properly handle
certain structures. A local attacker could potentially use this to expose
sensitive information (kernel memory). (CVE-2022-40768)

Update instructions:

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1138-gcp     4.15.0-1138.154
  linux-image-gcp-lts-18.04       4.15.0.1138.154

Ubuntu 16.04 ESM:
  linux-image-4.15.0-1138-gcp     4.15.0-1138.154~16.04.1
  linux-image-gcp                 4.15.0.1138.132
  linux-image-gke                 4.15.0.1138.132

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-5727-2
  https://ubuntu.com/security/notices/USN-5727-1
  CVE-2022-20422, CVE-2022-2153, CVE-2022-2978, CVE-2022-3028,
  CVE-2022-3635, CVE-2022-36879, CVE-2022-40768

Package Information:
  https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1138.154