USN-6396-1: Linux kernel vulnerabilities

26 September 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-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-4.15 - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-4.15 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-oracle - Linux kernel for Oracle Cloud systems

Details

It was discovered that some AMD x86-64 processors with SMT enabled could
speculatively execute instructions using a return address from a sibling
thread. A local attacker could possibly use this to expose sensitive
information. (CVE-2022-27672)

Daniel Moghimi discovered that some Intel(R) Processors did not properly
clear microarchitectural state after speculative execution of various
instructions. A local unprivileged user could use this to obtain to
sensitive information. (CVE-2022-40982)

Yang Lan discovered that the GFS2 file system implementation in the Linux
kernel could attempt to dereference a null pointer in some situations. An
attacker could use this to construct a malicious GFS2 image that, when
mounted and operated on, could cause a denial of service (system crash).
(CVE-2023-3212)

It was discovered that the NFC implementation in the Linux kernel contained
a use-after-free vulnerability when performing peer-to-peer communication
in certain conditions. A privileged attacker could use this to cause a
denial of service (system crash) or possibly expose sensitive information
(kernel memory). (CVE-2023-3863)

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)

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)

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Update instructions

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

Ubuntu 18.04
Ubuntu 16.04

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.

References

Related notices

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