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 SMB network file sharing protocol
implementation 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-2023-5345)

Lin Ma discovered that the netfilter subsystem in the Linux kernel did
not properly validate network family support while creating a new
netfilter table. A local attacker could use this to cause a denial of
service or possibly execute arbitrary code. (CVE-2023-6040)

It was discovered that the TLS subsystem in the Linux kernel did not
properly perform cryptographic operations in some situations, leading to
a null pointer dereference vulnerability. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2023-6176)

Xingyuan Mo discovered that the netfilter subsystem in the Linux kernel
did not properly handle inactive elements in its PIPAPO data structure,
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-2023-6817)

It was discovered that the IGMP protocol implementation in the Linux
kernel contained a race condition, 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-2023-6932)

Update instructions

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

Ubuntu 20.04 LTS
aws - 100.1
azure - 100.1
gcp - 100.1
generic - 100.1
gke - 100.1
gkeop - 100.1
ibm - 100.1
lowlatency - 100.1

Ubuntu 18.04 LTS
aws - 100.1
azure - 100.1
gcp - 100.1
generic - 100.1
lowlatency - 100.1

Ubuntu 16.04 ESM
aws - 100.1
azure - 100.1
gcp - 100.1
generic - 100.1
lowlatency - 100.1

Ubuntu 22.04 LTS
aws - 100.1
azure - 100.1
gcp - 100.1
generic - 100.1
gke - 100.1
ibm - 100.1

Ubuntu 14.04 ESM
generic - 100.1
lowlatency - 100.1

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-2023-5345
- CVE-2023-6040
- CVE-2023-6176
- CVE-2023-6817
- CVE-2023-6932