A Linux kernel security update has been released for Ubuntu Linux 16.04 ESM, 18.04 LTS and 20.04 LTS.

USN-5813-1: Linux kernel vulnerabilities

==========================================================================
Ubuntu Security Notice USN-5813-1
January 19, 2023

linux-aws-5.4, linux-gkeop, linux-hwe-5.4, linux-oracle, linux-snapdragon
vulnerabilities
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-gkeop: Linux kernel for Google Container Engine (GKE) systems
- linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems
- linux-hwe-5.4: Linux hardware enablement (HWE) kernel
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors

Details:

It was discovered that the NFSD implementation in the Linux kernel did not
properly handle some RPC messages, leading to a buffer overflow. A remote
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2022-43945)

Tamás Koczka discovered that the Bluetooth L2CAP handshake implementation
in the Linux kernel contained multiple use-after-free vulnerabilities. A
physically proximate attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2022-42896)

It was discovered that the Xen netback driver in the Linux kernel did not
properly handle packets structured in certain ways. An attacker in a guest
VM could possibly use this to cause a denial of service (host NIC
availability). (CVE-2022-3643)

It was discovered that an integer overflow vulnerability existed in the
Bluetooth subsystem in the Linux kernel. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2022-45934)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.4.0-1062-gkeop 5.4.0-1062.66
linux-image-gkeop 5.4.0.1062.60
linux-image-gkeop-5.4 5.4.0.1062.60

Ubuntu 18.04 LTS:
linux-image-4.15.0-1113-oracle 4.15.0-1113.124
linux-image-4.15.0-1144-snapdragon 4.15.0-1144.154
linux-image-5.4.0-1094-aws 5.4.0-1094.102~18.04.1
linux-image-5.4.0-137-generic 5.4.0-137.154~18.04.1
linux-image-5.4.0-137-generic-lpae 5.4.0-137.154~18.04.1
linux-image-5.4.0-137-lowlatency 5.4.0-137.154~18.04.1
linux-image-aws 5.4.0.1094.72
linux-image-generic-hwe-18.04 5.4.0.137.154~18.04.112
linux-image-generic-lpae-hwe-18.04 5.4.0.137.154~18.04.112
linux-image-lowlatency-hwe-18.04 5.4.0.137.154~18.04.112
linux-image-oem 5.4.0.137.154~18.04.112
linux-image-oem-osp1 5.4.0.137.154~18.04.112
linux-image-oracle-lts-18.04 4.15.0.1113.118
linux-image-snapdragon 4.15.0.1144.143
linux-image-snapdragon-hwe-18.04 5.4.0.137.154~18.04.112
linux-image-virtual-hwe-18.04 5.4.0.137.154~18.04.112

Ubuntu 16.04 ESM:
linux-image-4.15.0-1113-oracle 4.15.0-1113.124~16.04.1
linux-image-oracle 4.15.0.1113.95

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-5813-1
CVE-2022-3643, CVE-2022-42896, CVE-2022-43945, CVE-2022-45934

Package Information:
https://launchpad.net/ubuntu/+source/linux-gkeop/5.4.0-1062.66
https://launchpad.net/ubuntu/+source/linux-aws-5.4/5.4.0-1094.102~18.04.1
https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-137.154~18.04.1
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1113.124
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1144.154