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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM
- Ubuntu 22.04 LTS
- Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the kernel.

Software Description

- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems
- linux-azure - Linux kernel for Microsoft Azure Cloud systems
- linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
- linux-gke - Linux kernel for Google Container Engine (GKE) systems
- linux-gkeop - Linux kernel for Google Container Engine (GKE) systems
- linux-ibm - Linux kernel for IBM cloud systems

Details

It was discovered that the IP-VLAN network driver for the Linux kernel
did not properly initialize memory in some situations, leading to an
out-of- bounds write vulnerability. An attacker could use this to cause
a denial of service (system crash) or possibly execute arbitrary code.
(CVE-2023-3090)

It was discovered that the virtual terminal driver in the Linux kernel
contained a use-after-free vulnerability. A local attacker could use
this to cause a denial of service (system crash) or possibly expose
sensitive information (kernel memory). (CVE-2023-3567)

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 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)

It was discovered that some network classifier implementations in the
Linux kernel contained use-after-free vulnerabilities. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2023-4128)

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 bluetooth subsystem in the Linux kernel did
not properly handle L2CAP socket release, 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-2023-40283)

Update instructions

The problem can be corrected by updating your kernel livepatch to the
following versions:

Ubuntu 20.04 LTS
aws - 98.1
azure - 98.1
gcp - 98.1
generic - 98.1
gke - 98.1
gkeop - 98.1
ibm - 98.1
lowlatency - 98.1

Ubuntu 18.04 LTS
aws - 98.1
azure - 98.1
gcp - 98.1
generic - 98.1
generic - 98.2
lowlatency - 98.1
lowlatency - 98.2

Ubuntu 16.04 ESM
aws - 98.1
azure - 98.1
gcp - 98.1
generic - 98.1
lowlatency - 98.1

Ubuntu 22.04 LTS
aws - 98.1
aws - 98.2
azure - 98.1
azure - 98.2
gcp - 98.1
gcp - 98.3
generic - 98.1
generic - 98.2
gke - 98.1
ibm - 98.1

Ubuntu 14.04 ESM
generic - 98.1
lowlatency - 98.1

Support Information

Livepatches for supported LTS kernels will receive upgrades for a period
of up to 13 months after the build date of the kernel.

Livepatches for supported HWE kernels which are not based on an LTS
kernel version will receive upgrades for a period of up to 9 months
after the build date of the kernel, or until the end of support for that
kernel’s non-LTS distro release version, whichever is sooner.

References

- CVE-2023-3090
- CVE-2023-3567
- CVE-2023-3609
- CVE-2023-3776
- CVE-2023-3777
- CVE-2023-3995
- CVE-2023-4004
- CVE-2023-4128
- CVE-2023-21400
- CVE-2023-40283