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

[USN-6131-1] Linux kernel vulnerabilities

==========================================================================
Ubuntu Security Notice USN-6131-1
June 01, 2023

linux, linux-aws, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4,
linux-gke, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4,
linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 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-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-gke: Linux kernel for Google Container Engine (GKE) systems
- linux-gkeop: Linux kernel for Google Container Engine (GKE) systems
- linux-ibm: Linux kernel for IBM cloud systems
- linux-kvm: Linux kernel for cloud environments
- linux-oracle: Linux kernel for Oracle Cloud 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

Details:

Patryk Sondej and Piotr Krysiuk discovered that a race condition existed in
the netfilter subsystem of the Linux kernel when processing batch requests,
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-2023-32233)

Gwangun Jung discovered that the Quick Fair Queueing scheduler
implementation in the Linux kernel contained an out-of-bounds write
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2023-31436)

Reima Ishii discovered that the nested KVM implementation for Intel x86
processors in the Linux kernel did not properly validate control registers
in certain situations. An attacker in a guest VM could use this to cause a
denial of service (guest crash). (CVE-2023-30456)

It was discovered that the Broadcom FullMAC USB WiFi driver in the Linux
kernel did not properly perform data buffer size validation in some
situations. A physically proximate attacker could use this to craft a
malicious USB device that when inserted, could cause a denial of service
(system crash) or possibly expose sensitive information. (CVE-2023-1380)

Jean-Baptiste Cayrou discovered that the shiftfs file system in the Ubuntu
Linux kernel contained a race condition when handling inode locking in some
situations. A local attacker could use this to cause a denial of service
(kernel deadlock). (CVE-2023-2612)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.4.0-1050-ibm 5.4.0-1050.55
linux-image-5.4.0-1070-gkeop 5.4.0-1070.74
linux-image-5.4.0-1092-kvm 5.4.0-1092.98
linux-image-5.4.0-1100-gke 5.4.0-1100.107
linux-image-5.4.0-1102-oracle 5.4.0-1102.111
linux-image-5.4.0-1103-aws 5.4.0-1103.111
linux-image-5.4.0-1106-gcp 5.4.0-1106.115
linux-image-5.4.0-1109-azure 5.4.0-1109.115
linux-image-5.4.0-150-generic 5.4.0-150.167
linux-image-5.4.0-150-generic-lpae 5.4.0-150.167
linux-image-5.4.0-150-lowlatency 5.4.0-150.167
linux-image-aws-lts-20.04 5.4.0.1103.100
linux-image-azure-lts-20.04 5.4.0.1109.102
linux-image-gcp-lts-20.04 5.4.0.1106.108
linux-image-generic 5.4.0.150.148
linux-image-generic-lpae 5.4.0.150.148
linux-image-gke 5.4.0.1100.105
linux-image-gke-5.4 5.4.0.1100.105
linux-image-gkeop 5.4.0.1070.68
linux-image-gkeop-5.4 5.4.0.1070.68
linux-image-ibm 5.4.0.1050.76
linux-image-ibm-lts-20.04 5.4.0.1050.76
linux-image-kvm 5.4.0.1092.87
linux-image-lowlatency 5.4.0.150.148
linux-image-oem 5.4.0.150.148
linux-image-oem-osp1 5.4.0.150.148
linux-image-oracle-lts-20.04 5.4.0.1102.95
linux-image-virtual 5.4.0.150.148

Ubuntu 18.04 LTS:
linux-image-5.4.0-1050-ibm 5.4.0-1050.55~18.04.1
linux-image-5.4.0-1102-oracle 5.4.0-1102.111~18.04.1
linux-image-5.4.0-1106-gcp 5.4.0-1106.115~18.04.1
linux-image-5.4.0-1109-azure 5.4.0-1109.115~18.04.1
linux-image-5.4.0-150-generic 5.4.0-150.167~18.04.1
linux-image-5.4.0-150-generic-lpae 5.4.0-150.167~18.04.1
linux-image-5.4.0-150-lowlatency 5.4.0-150.167~18.04.1
linux-image-azure 5.4.0.1109.82
linux-image-gcp 5.4.0.1106.82
linux-image-generic-hwe-18.04 5.4.0.150.167~18.04.121
linux-image-generic-lpae-hwe-18.04 5.4.0.150.167~18.04.121
linux-image-ibm 5.4.0.1050.61
linux-image-lowlatency-hwe-18.04 5.4.0.150.167~18.04.121
linux-image-oem 5.4.0.150.167~18.04.121
linux-image-oem-osp1 5.4.0.150.167~18.04.121
linux-image-oracle 5.4.0.1102.111~18.04.74
linux-image-snapdragon-hwe-18.04 5.4.0.150.167~18.04.121
linux-image-virtual-hwe-18.04 5.4.0.150.167~18.04.121

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-6131-1
CVE-2023-1380, CVE-2023-2612, CVE-2023-30456, CVE-2023-31436,
CVE-2023-32233

Package Information:
https://launchpad.net/ubuntu/+source/linux/5.4.0-150.167
https://launchpad.net/ubuntu/+source/linux-aws/5.4.0-1103.111
https://launchpad.net/ubuntu/+source/linux-azure/5.4.0-1109.115
https://launchpad.net/ubuntu/+source/linux-gcp/5.4.0-1106.115
https://launchpad.net/ubuntu/+source/linux-gke/5.4.0-1100.107
https://launchpad.net/ubuntu/+source/linux-gkeop/5.4.0-1070.74
https://launchpad.net/ubuntu/+source/linux-ibm/5.4.0-1050.55
https://launchpad.net/ubuntu/+source/linux-kvm/5.4.0-1092.98
https://launchpad.net/ubuntu/+source/linux-oracle/5.4.0-1102.111
https://launchpad.net/ubuntu/+source/linux-azure-5.4/5.4.0-1109.115~18.04.1
https://launchpad.net/ubuntu/+source/linux-gcp-5.4/5.4.0-1106.115~18.04.1
https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-150.167~18.04.1
https://launchpad.net/ubuntu/+source/linux-ibm-5.4/5.4.0-1050.55~18.04.1
https://launchpad.net/ubuntu/+source/linux-oracle-5.4/5.4.0-1102.111~18.04.1