A Linux kernel security update has been released for Ubuntu Linux 18.04 LTS.

USN-5669-1: Linux kernel vulnerabilities

==========================================================================
Ubuntu Security Notice USN-5669-1
October 10, 2022

linux, linux-dell300x, linux-kvm, linux-oracle, linux-raspi2,
linux-snapdragon vulnerabilities
==========================================================================

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

- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux: Linux kernel
- linux-dell300x: Linux kernel for Dell 300x platforms
- linux-kvm: Linux kernel for cloud environments
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-raspi2: Linux kernel for Raspberry Pi systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors

Details:

It was discovered that the SUNRPC RDMA protocol implementation in the Linux
kernel did not properly calculate the header size of a RPC message payload.
A local attacker could use this to expose sensitive information (kernel
memory). (CVE-2022-0812)

Moshe Kol, Amit Klein and Yossi Gilad discovered that the IP implementation
in the Linux kernel did not provide sufficient randomization when
calculating port offsets. An attacker could possibly use this to expose
sensitive information. (CVE-2022-1012, CVE-2022-32296)

Duoming Zhou discovered that race conditions existed in the timer handling
implementation of the Linux kernel's Rose X.25 protocol layer, resulting in
use-after-free vulnerabilities. A local attacker could use this to cause a
denial of service (system crash). (CVE-2022-2318)

Roger Pau Monné discovered that the Xen virtual block driver in the Linux
kernel did not properly initialize memory pages to be used for shared
communication with the backend. A local attacker could use this to expose
sensitive information (guest kernel memory). (CVE-2022-26365)

Roger Pau Monné discovered that the Xen paravirtualization frontend in the
Linux kernel did not properly initialize memory pages to be used for shared
communication with the backend. A local attacker could use this to expose
sensitive information (guest kernel memory). (CVE-2022-33740)

It was discovered that the Xen paravirtualization frontend in the Linux
kernel incorrectly shared unrelated data when communicating with certain
backends. A local attacker could use this to cause a denial of service
(guest crash) or expose sensitive information (guest kernel memory).
(CVE-2022-33741, CVE-2022-33742)

Oleksandr Tyshchenko discovered that the Xen paravirtualization platform in
the Linux kernel on ARM platforms contained a race condition in certain
situations. An attacker in a guest VM could use this to cause a denial of
service in the host OS. (CVE-2022-33744)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1054-dell300x 4.15.0-1054.59
linux-image-4.15.0-1107-oracle 4.15.0-1107.118
linux-image-4.15.0-1120-raspi2 4.15.0-1120.128
linux-image-4.15.0-1128-kvm 4.15.0-1128.133
linux-image-4.15.0-1138-snapdragon 4.15.0-1138.148
linux-image-4.15.0-194-generic 4.15.0-194.205
linux-image-4.15.0-194-generic-lpae 4.15.0-194.205
linux-image-4.15.0-194-lowlatency 4.15.0-194.205
linux-image-dell300x 4.15.0.1054.54
linux-image-generic 4.15.0.194.179
linux-image-generic-lpae 4.15.0.194.179
linux-image-kvm 4.15.0.1128.121
linux-image-lowlatency 4.15.0.194.179
linux-image-oracle-lts-18.04 4.15.0.1107.114
linux-image-raspi2 4.15.0.1120.117
linux-image-snapdragon 4.15.0.1138.139
linux-image-virtual 4.15.0.194.179

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-5669-1
CVE-2022-0812, CVE-2022-1012, CVE-2022-2318, CVE-2022-26365,
CVE-2022-32296, CVE-2022-33740, CVE-2022-33741, CVE-2022-33742,
CVE-2022-33744

Package Information:
https://launchpad.net/ubuntu/+source/linux/4.15.0-194.205
https://launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1054.59
https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1128.133
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1107.118
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1120.128
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1138.148