==========================================================================
Ubuntu Security Notice USN-5926-1
March 06, 2023

linux, linux-aws, linux-kvm, linux-lts-xenial vulnerabilities
==========================================================================

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

- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux: Linux kernel
- linux-kvm: Linux kernel for cloud environments
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- 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)

Update instructions:

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

Ubuntu 16.04 ESM:
   linux-image-4.4.0-1117-kvm      4.4.0-1117.127
   linux-image-4.4.0-237-generic   4.4.0-237.271+1
   linux-image-4.4.0-237-lowlatency  4.4.0-237.271+1
   linux-image-generic             4.4.0.237.243
   linux-image-generic-lts-xenial  4.4.0.237.243
   linux-image-kvm                 4.4.0.1117.114
   linux-image-lowlatency          4.4.0.237.243
   linux-image-lowlatency-lts-xenial  4.4.0.237.243
   linux-image-virtual             4.4.0.237.243
   linux-image-virtual-lts-xenial  4.4.0.237.243

Ubuntu 14.04 ESM:
   linux-image-4.4.0-1116-aws      4.4.0-1116.122
   linux-image-4.4.0-237-generic   4.4.0-237.271~14.04.1
   linux-image-4.4.0-237-lowlatency  4.4.0-237.271~14.04.1
   linux-image-aws                 4.4.0.1116.113
   linux-image-generic-lts-xenial  4.4.0.237.206
   linux-image-lowlatency-lts-xenial  4.4.0.237.206
   linux-image-virtual-lts-xenial  4.4.0.237.206

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-5926-1
   CVE-2021-4155, CVE-2022-20566, CVE-2022-41858, CVE-2022-42895,
   CVE-2023-0045, CVE-2023-23559