A Linux kernel security update has been released for Ubuntu Linux 20.04 LTS and 22.04 LTS.

[USN-6348-1] Linux kernel vulnerabilities

==========================================================================
Ubuntu Security Notice USN-6348-1
September 06, 2023

linux-intel-iotg-5.15, linux-raspi 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-raspi: Linux kernel for Raspberry Pi systems
- linux-intel-iotg-5.15: Linux kernel for Intel IoT platforms

Details:

Daniel Moghimi discovered that some Intel(R) Processors did not properly
clear microarchitectural state after speculative execution of various
instructions. A local unprivileged user could use this to obtain to
sensitive information. (CVE-2022-40982)

Tavis Ormandy discovered that some AMD processors did not properly handle
speculative execution of certain vector register instructions. A local
attacker could use this to expose sensitive information. (CVE-2023-20593)

Ye Zhang and Nicolas Wu discovered that the io_uring subsystem in the Linux
kernel did not properly handle locking for rings with IOPOLL, leading to a
double-free vulnerability. A local attacker could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(CVE-2023-21400)

It was discovered that the universal 32bit network packet classifier
implementation in the Linux kernel did not properly perform reference
counting in some situations, 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-2023-3609)

It was discovered that the netfilter subsystem in the Linux kernel did not
properly handle certain error conditions, 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-2023-3610)

It was discovered that the Quick Fair Queueing network 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-2023-3611)

It was discovered that the network packet classifier with
netfilter/firewall marks implementation in the Linux kernel did not
properly handle reference counting, 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-2023-3776)

Kevin Rich discovered that the netfilter subsystem in the Linux kernel did
not properly handle table rules flush in certain circumstances. A local
attacker could possibly use this to cause a denial of service (system
crash) or execute arbitrary code. (CVE-2023-3777)

Kevin Rich discovered that the netfilter subsystem in the Linux kernel did
not properly handle rule additions to bound chains in certain
circumstances. A local attacker could possibly use this to cause a denial
of service (system crash) or execute arbitrary code. (CVE-2023-3995)

It was discovered that the netfilter subsystem in the Linux kernel did not
properly handle PIPAPO element removal, leading to a use-after-free
vulnerability. A local attacker could possibly use this to cause a denial
of service (system crash) or execute arbitrary code. (CVE-2023-4004)

Kevin Rich discovered that the netfilter subsystem in the Linux kernel did
not properly handle bound chain deactivation in certain circumstances. A
local attacker could possibly use this to cause a denial of service (system
crash) or execute arbitrary code. (CVE-2023-4015)

Update instructions:

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

Ubuntu 22.04 LTS:
linux-image-5.15.0-1036-raspi 5.15.0-1036.39
linux-image-raspi 5.15.0.1036.34
linux-image-raspi-nolpae 5.15.0.1036.34

Ubuntu 20.04 LTS:
linux-image-5.15.0-1038-intel-iotg 5.15.0-1038.43~20.04.1
linux-image-intel 5.15.0.1038.43~20.04.28
linux-image-intel-iotg 5.15.0.1038.43~20.04.28

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-6348-1
CVE-2022-40982, CVE-2023-20593, CVE-2023-21400, CVE-2023-3609,
CVE-2023-3610, CVE-2023-3611, CVE-2023-3776, CVE-2023-3777,
CVE-2023-3995, CVE-2023-4004, CVE-2023-4015

Package Information:
https://launchpad.net/ubuntu/+source/linux-raspi/5.15.0-1036.39

https://launchpad.net/ubuntu/+source/linux-intel-iotg-5.15/5.15.0-1038.43~20.04.1