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A Linux kernel (Azure CVM) security update has been released for Ubuntu Linux 20.04 LTS and 22.04 LTS.



[USN-6135-1] Linux kernel (Azure CVM) vulnerabilities


==========================================================================
Ubuntu Security Notice USN-6135-1
June 02, 2023

linux-azure-fde, linux-azure-fde-5.15 vulnerabilities
==========================================================================

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure-fde: Linux kernel for Microsoft Azure CVM cloud systems
- linux-azure-fde-5.15: Linux kernel for Microsoft Azure CVM 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 22.04 LTS:
linux-image-5.15.0-1039-azure-fde 5.15.0-1039.46.1
linux-image-azure-fde 5.15.0.1039.46.16

Ubuntu 20.04 LTS:
linux-image-5.15.0-1039-azure-fde 5.15.0-1039.46~20.04.1.1
linux-image-azure-fde 5.15.0.1039.46~20.04.1.18

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-6135-1
CVE-2023-1380, CVE-2023-2612, CVE-2023-30456, CVE-2023-31436,
CVE-2023-32233

Package Information:
https://launchpad.net/ubuntu/+source/linux-azure-fde/5.15.0-1039.46.1

https://launchpad.net/ubuntu/+source/linux-azure-fde-5.15/5.15.0-1039.46~20.04.1.1