A Linux kernel (IoT) security update has been released for Ubuntu Linux 20.04 LTS.

[USN-6462-2] Linux kernel (IoT) vulnerabilities

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Ubuntu Security Notice USN-6462-2
November 10, 2023

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

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-iot: Linux kernel for IoT platforms

Details:

Seth Jenkins discovered that the Linux kernel did not properly perform
address randomization for a per-cpu memory management structure. A local
attacker could use this to expose sensitive information (kernel memory) or
in conjunction with another kernel vulnerability. (CVE-2023-0597)

Yu Hao and Weiteng Chen discovered that the Bluetooth HCI UART driver in
the Linux kernel contained a race condition, leading to a null pointer
dereference vulnerability. A local attacker could use this to cause a
denial of service (system crash). (CVE-2023-31083)

Lin Ma discovered that the Netlink Transformation (XFRM) subsystem in the
Linux kernel contained a null pointer dereference vulnerability in some
situations. A local privileged attacker could use this to cause a denial of
service (system crash). (CVE-2023-3772)

It was discovered that the Siano USB MDTV receiver device driver in the
Linux kernel did not properly handle device initialization failures in
certain situations, leading to a use-after-free vulnerability. A physically
proximate attacker could use this cause a denial of service (system crash).
(CVE-2023-4132)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.4.0-1025-iot 5.4.0-1025.26

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-6462-2
https://ubuntu.com/security/notices/USN-6462-1
CVE-2023-0597, CVE-2023-31083, CVE-2023-3772, CVE-2023-4132

Package Information:
https://launchpad.net/ubuntu/+source/linux-iot/5.4.0-1025.26