A Linux kernel (Azure CVM) security update has been released for Ubuntu Linux 22.04 LTS to address several security issues.

USN-5831-1: Linux kernel (Azure CVM) vulnerabilities

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Ubuntu Security Notice USN-5831-1
January 27, 2023

linux-azure-fde vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure-fde: Linux kernel for Microsoft Azure CVM cloud systems

Details:

Kyle Zeng discovered that the sysctl implementation in the Linux kernel
contained a stack-based buffer overflow. A local attacker could use this to
cause a denial of service (system crash) or execute arbitrary code.
(CVE-2022-4378)

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 22.04 LTS:
linux-image-5.15.0-1031-azure-fde 5.15.0-1031.38.1
linux-image-azure-fde 5.15.0.1031.38.8

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-5831-1
CVE-2022-3643, CVE-2022-42896, CVE-2022-4378, CVE-2022-45934

Package Information:
https://launchpad.net/ubuntu/+source/linux-azure-fde/5.15.0-1031.38.1