1. Ubuntu Security Notices
  2. USN-6396-1

USN-6396-1: Linux kernel vulnerabilities

Publication date

26 September 2023

Overview

Several security issues were fixed in the Linux kernel.

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...

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)

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release Package Version
18.04 bionic linux-image-4.15.0-1124-oracle –  4.15.0-1124.135  
linux-image-4.15.0-1155-gcp –  4.15.0-1155.172  
linux-image-4.15.0-1161-aws –  4.15.0-1161.174  
linux-image-4.15.0-1170-azure –  4.15.0-1170.185  
linux-image-4.15.0-218-generic –  4.15.0-218.229  
linux-image-4.15.0-218-lowlatency –  4.15.0-218.229  
linux-image-aws-lts-18.04 –  4.15.0.1161.159  
linux-image-azure-lts-18.04 –  4.15.0.1170.138  
linux-image-gcp-lts-18.04 –  4.15.0.1155.169  
linux-image-generic –  4.15.0.218.202  
linux-image-lowlatency –  4.15.0.218.202  
linux-image-oracle-lts-18.04 –  4.15.0.1124.129  
linux-image-virtual –  4.15.0.218.202  
16.04 xenial linux-image-4.15.0-1124-oracle –  4.15.0-1124.135~16.04.1  
linux-image-4.15.0-1155-gcp –  4.15.0-1155.172~16.04.1  
linux-image-4.15.0-1161-aws –  4.15.0-1161.174~16.04.1  
linux-image-4.15.0-1170-azure –  4.15.0-1170.185~16.04.1  
linux-image-4.15.0-218-generic –  4.15.0-218.229~16.04.1  
linux-image-4.15.0-218-lowlatency –  4.15.0-218.229~16.04.1  
linux-image-aws-hwe –  4.15.0.1161.144  
linux-image-azure –  4.15.0.1170.154  
linux-image-gcp –  4.15.0.1155.145  
linux-image-generic-hwe-16.04 –  4.15.0.218.2  
linux-image-gke –  4.15.0.1155.145  
linux-image-lowlatency-hwe-16.04 –  4.15.0.218.2  
linux-image-oem –  4.15.0.218.2  
linux-image-oracle –  4.15.0.1124.105  
linux-image-virtual-hwe-16.04 –  4.15.0.218.2  

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References

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