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

USN-5985-1: Linux kernel vulnerabilities

==========================================================================
Ubuntu Security Notice USN-5985-1
March 29, 2023

linux-aws-5.4, linux-azure-5.4, linux-gcp-5.4, linux-hwe-5.4,
linux-ibm-5.4, linux-oracle-5.4, linux-raspi-5.4 vulnerabilities
==========================================================================

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

- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems
- linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems
- linux-gcp-5.4: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe-5.4: Linux hardware enablement (HWE) kernel
- linux-ibm-5.4: Linux kernel for IBM cloud systems
- linux-oracle-5.4: Linux kernel for Oracle Cloud systems
- linux-raspi-5.4: Linux kernel for Raspberry Pi systems

Details:

It was discovered that the System V IPC implementation in the Linux kernel
did not properly handle large shared memory counts. A local attacker could
use this to cause a denial of service (memory exhaustion). (CVE-2021-3669)

It was discovered that the KVM VMX implementation in the Linux kernel did
not properly handle indirect branch prediction isolation between L1 and L2
VMs. An attacker in a guest VM could use this to expose sensitive
information from the host OS or other guest VMs. (CVE-2022-2196)

Gerald Lee discovered that the USB Gadget file system implementation in the
Linux kernel contained a race condition, leading to a use-after-free
vulnerability in some situations. A local attacker could use this to cause
a denial of service (system crash) or possibly execute arbitrary code.
(CVE-2022-4382)

It was discovered that the RNDIS USB driver in the Linux kernel contained
an integer overflow vulnerability. A local attacker with physical access
could plug in a malicious USB device to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2023-23559)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-5.4.0-1046-ibm 5.4.0-1046.51~18.04.1
linux-image-5.4.0-1082-raspi 5.4.0-1082.93~18.04.1
linux-image-5.4.0-1098-oracle 5.4.0-1098.107~18.04.1
linux-image-5.4.0-1099-aws 5.4.0-1099.107~18.04.1
linux-image-5.4.0-1102-gcp 5.4.0-1102.111~18.04.2
linux-image-5.4.0-1105-azure 5.4.0-1105.111~18.04.1
linux-image-5.4.0-146-generic 5.4.0-146.163~18.04.1
linux-image-5.4.0-146-generic-lpae 5.4.0-146.163~18.04.1
linux-image-5.4.0-146-lowlatency 5.4.0-146.163~18.04.1
linux-image-aws 5.4.0.1099.77
linux-image-azure 5.4.0.1105.78
linux-image-gcp 5.4.0.1102.78
linux-image-generic-hwe-18.04 5.4.0.146.163~18.04.117
linux-image-generic-lpae-hwe-18.04 5.4.0.146.163~18.04.117
linux-image-ibm 5.4.0.1046.57
linux-image-lowlatency-hwe-18.04 5.4.0.146.163~18.04.117
linux-image-oem 5.4.0.146.163~18.04.117
linux-image-oem-osp1 5.4.0.146.163~18.04.117
linux-image-oracle 5.4.0.1098.107~18.04.70
linux-image-raspi-hwe-18.04 5.4.0.1082.79
linux-image-snapdragon-hwe-18.04 5.4.0.146.163~18.04.117
linux-image-virtual-hwe-18.04 5.4.0.146.163~18.04.117

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-5985-1
CVE-2021-3669, CVE-2022-2196, CVE-2022-4382, CVE-2023-23559

Package Information:
https://launchpad.net/ubuntu/+source/linux-aws-5.4/5.4.0-1099.107~18.04.1
https://launchpad.net/ubuntu/+source/linux-azure-5.4/5.4.0-1105.111~18.04.1
https://launchpad.net/ubuntu/+source/linux-gcp-5.4/5.4.0-1102.111~18.04.2
https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-146.163~18.04.1
https://launchpad.net/ubuntu/+source/linux-ibm-5.4/5.4.0-1046.51~18.04.1
https://launchpad.net/ubuntu/+source/linux-oracle-5.4/5.4.0-1098.107~18.04.1
https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1082.93~18.04.1