USN-5338-1: Linux kernel vulnerabilities

22 March 2022

Several security issues were fixed in the Linux kernel.

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Releases

Packages

Details

Yiqi Sun and Kevin Wang discovered that the cgroups implementation in the
Linux kernel did not properly restrict access to the cgroups v1
release_agent feature. A local attacker could use this to gain
administrative privileges. (CVE-2022-0492)

Jürgen Groß discovered that the Xen subsystem within the Linux kernel did
not adequately limit the number of events driver domains (unprivileged PV
backends) could send to other guest VMs. An attacker in a driver domain
could use this to cause a denial of service in other guest VMs.
(CVE-2021-28711, CVE-2021-28712, CVE-2021-28713)

Jürgen Groß discovered that the Xen network backend driver in the Linux
kernel did not adequately limit the amount of queued packets when a guest
did not process them. An attacker in a guest VM can use this to cause a
denial of service (excessive kernel memory consumption) in the network
backend domain. (CVE-2021-28714, CVE-2021-28715)

It was discovered that the simulated networking device driver for the Linux
kernel did not properly initialize memory in certain situations. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2021-4135)

Brendan Dolan-Gavitt discovered that the Marvell WiFi-Ex USB device driver
in the Linux kernel did not properly handle some error conditions. A
physically proximate attacker could use this to cause a denial of service
(system crash). (CVE-2021-43976)

It was discovered that the ARM Trusted Execution Environment (TEE)
subsystem 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 or possibly execute arbitrary code. (CVE-2021-44733)

It was discovered that the Phone Network protocol (PhoNet) implementation
in the Linux kernel did not properly perform reference counting in some
error conditions. A local attacker could possibly use this to cause a
denial of service (memory exhaustion). (CVE-2021-45095)

It was discovered that the Reliable Datagram Sockets (RDS) protocol
implementation in the Linux kernel did not properly deallocate memory in
some error conditions. A local attacker could possibly use this to cause a
denial of service (memory exhaustion). (CVE-2021-45480)

Samuel Page discovered that the Transparent Inter-Process Communication
(TIPC) protocol implementation in the Linux kernel contained a stack-based
buffer overflow. A remote attacker could use this to cause a denial of
service (system crash) for systems that have a TIPC bearer configured.
(CVE-2022-0435)

It was discovered that the KVM implementation for s390 systems in the Linux
kernel did not properly prevent memory operations on PVM guests that were
in non-protected mode. A local attacker could use this to obtain
unauthorized memory write access. (CVE-2022-0516)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 20.04
Ubuntu 18.04

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.