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

USN-5565-1: Linux kernel vulnerabilities

=========================================================================
Ubuntu Security Notice USN-5565-1
August 10, 2022

linux, linux-hwe-5.15, linux-lowlatency, linux-lowlatency-hwe-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: Linux kernel
- linux-lowlatency: Linux low latency kernel
- linux-hwe-5.15: Linux hardware enablement (HWE) kernel
- linux-lowlatency-hwe-5.15: Linux low latency kernel

Details:

Zhenpeng Lin discovered that the network packet scheduler implementation in
the Linux kernel did not properly remove all references to a route filter
before freeing it in some situations. A local attacker could use this to
cause a denial of service (system crash) or execute arbitrary code.
(CVE-2022-2588)

It was discovered that the netfilter subsystem of the Linux kernel did not
prevent one nft object from referencing an nft set in another nft table,
leading to a use-after-free vulnerability. A local attacker could use this
to cause a denial of service (system crash) or execute arbitrary code.
(CVE-2022-2586)

It was discovered that the implementation of POSIX timers in the Linux
kernel did not properly clean up timers in some situations. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2022-2585)

Johannes Wikner and Kaveh Razavi discovered that for some AMD x86-64
processors, the branch predictor could by mis-trained for return
instructions in certain circumstances. A local attacker could possibly use
this to expose sensitive information. (CVE-2022-29900)

Johannes Wikner and Kaveh Razavi discovered that for some Intel x86-64
processors, the Linux kernel's protections against speculative branch
target injection attacks were insufficient in some circumstances. A local
attacker could possibly use this to expose sensitive information.
(CVE-2022-29901)

Update instructions:

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

Ubuntu 22.04 LTS:
linux-image-5.15.0-46-generic 5.15.0-46.49
linux-image-5.15.0-46-generic-64k 5.15.0-46.49
linux-image-5.15.0-46-generic-lpae 5.15.0-46.49
linux-image-5.15.0-46-lowlatency 5.15.0-46.49
linux-image-5.15.0-46-lowlatency-64k 5.15.0-46.49
linux-image-generic 5.15.0.46.46
linux-image-generic-64k 5.15.0.46.46
linux-image-generic-64k-hwe-22.04 5.15.0.46.46
linux-image-generic-hwe-22.04 5.15.0.46.46
linux-image-generic-lpae 5.15.0.46.46
linux-image-generic-lpae-hwe-22.04 5.15.0.46.46
linux-image-lowlatency 5.15.0.46.43
linux-image-lowlatency-64k 5.15.0.46.43
linux-image-lowlatency-64k-hwe-22.04 5.15.0.46.43
linux-image-lowlatency-hwe-22.04 5.15.0.46.43
linux-image-virtual 5.15.0.46.46
linux-image-virtual-hwe-22.04 5.15.0.46.46

Ubuntu 20.04 LTS:
linux-image-5.15.0-46-generic 5.15.0-46.49~20.04.1
linux-image-5.15.0-46-generic-64k 5.15.0-46.49~20.04.1
linux-image-5.15.0-46-generic-lpae 5.15.0-46.49~20.04.1
linux-image-5.15.0-46-lowlatency 5.15.0-46.49~20.04.1
linux-image-5.15.0-46-lowlatency-64k 5.15.0-46.49~20.04.1
linux-image-generic-64k-hwe-20.04 5.15.0.46.49~20.04.16
linux-image-generic-hwe-20.04 5.15.0.46.49~20.04.16
linux-image-generic-lpae-hwe-20.04 5.15.0.46.49~20.04.16
linux-image-lowlatency-64k-hwe-20.04 5.15.0.46.49~20.04.15
linux-image-lowlatency-hwe-20.04 5.15.0.46.49~20.04.15
linux-image-virtual-hwe-20.04 5.15.0.46.49~20.04.16

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-5565-1
CVE-2022-2585, CVE-2022-2586, CVE-2022-2588, CVE-2022-29900,
CVE-2022-29901

Package Information:
https://launchpad.net/ubuntu/+source/linux/5.15.0-46.49
https://launchpad.net/ubuntu/+source/linux-lowlatency/5.15.0-46.49
https://launchpad.net/ubuntu/+source/linux-hwe-5.15/5.15.0-46.49~20.04.1

https://launchpad.net/ubuntu/+source/linux-lowlatency-hwe-5.15/5.15.0-46.49~20.04.1