USN-5926-1: Linux kernel vulnerabilities

6 March 2023

Several security issues were fixed in the Linux kernel.

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Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

Kirill Tkhai discovered that the XFS file system implementation in the
Linux kernel did not calculate size correctly when pre-allocating space in
some situations. A local attacker could use this to expose sensitive
information. (CVE-2021-4155)

Lee Jones discovered that a use-after-free vulnerability existed in the
Bluetooth implementation in the Linux kernel. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2022-20566)

Duoming Zhou discovered that a race condition existed in the SLIP driver in
the Linux kernel, leading to a null pointer dereference vulnerability. An
attacker could use this to cause a denial of service (system crash).
(CVE-2022-41858)

Tamás Koczka discovered that the Bluetooth L2CAP implementation in the
Linux kernel did not properly initialize memory in some situations. A
physically proximate attacker could possibly use this to expose sensitive
information (kernel memory). (CVE-2022-42895)

José Oliveira and Rodrigo Branco discovered that the prctl syscall
implementation in the Linux kernel did not properly protect against
indirect branch prediction attacks in some situations. A local attacker
could possibly use this to expose sensitive information. (CVE-2023-0045)

It was discovered that the RNDIS USB driver in the Linux kernel contained
an integer overflow vulnerability. A local attacker with physical access
could plug in a malicious USB device to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2023-23559)

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 16.04
Ubuntu 14.04

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.