1. Ubuntu Security Notices
  2. USN-4977-1

USN-4977-1: Linux kernel vulnerabilities

Publication date

3 June 2021

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-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi - Linux kernel for Raspberry Pi (V8) systems

Details

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel contained a reference counting error. A local attacker could
use this to cause a denial of service (system crash). (CVE-2020-25670)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel did not properly deallocate memory in certain error
situations. A local attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2020-25671, CVE-2020-25672)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel did not properly handle error conditions in some situations,
leading to an infinite loop. A local attacker could use this to cause a
denial of service. (CVE-2020-25673)

Piotr Krysiuk and Benedict Schlueter discovered that...

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel contained a reference counting error. A local attacker could
use this to cause a denial of service (system crash). (CVE-2020-25670)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel did not properly deallocate memory in certain error
situations. A local attacker could use this to cause a denial of service
(memory exhaustion). (CVE-2020-25671, CVE-2020-25672)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the
Linux kernel did not properly handle error conditions in some situations,
leading to an infinite loop. A local attacker could use this to cause a
denial of service. (CVE-2020-25673)

Piotr Krysiuk and Benedict Schlueter discovered that the eBPF
implementation in the Linux kernel performed out of bounds speculation on
pointer arithmetic. A local attacker could use this to expose sensitive
information. (CVE-2021-29155)

Reiji Watanabe discovered that the KVM VMX implementation in the Linux
kernel did not properly prevent user space from tampering with an array
index value, leading to a potential out-of-bounds write. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-3501)

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
21.04 hirsute linux-image-5.11.0-1006-azure –  5.11.0-1006.6
linux-image-5.11.0-1007-oracle –  5.11.0-1007.7
linux-image-5.11.0-1008-aws –  5.11.0-1008.8
linux-image-5.11.0-1008-gcp –  5.11.0-1008.9
linux-image-5.11.0-1008-kvm –  5.11.0-1008.8
linux-image-5.11.0-1009-raspi –  5.11.0-1009.10
linux-image-5.11.0-1009-raspi-nolpae –  5.11.0-1009.10
linux-image-5.11.0-18-generic –  5.11.0-18.19
linux-image-5.11.0-18-generic-64k –  5.11.0-18.19
linux-image-5.11.0-18-generic-lpae –  5.11.0-18.19
linux-image-5.11.0-18-lowlatency –  5.11.0-18.19
linux-image-aws –  5.11.0.1008.8
linux-image-azure –  5.11.0.1006.6
linux-image-gcp –  5.11.0.1008.8
linux-image-generic –  5.11.0.18.19
linux-image-generic-64k –  5.11.0.18.19
linux-image-generic-lpae –  5.11.0.18.19
linux-image-gke –  5.11.0.1008.8
linux-image-kvm –  5.11.0.1008.8
linux-image-lowlatency –  5.11.0.18.19
linux-image-oracle –  5.11.0.1007.7
linux-image-raspi –  5.11.0.1009.7
linux-image-raspi-nolpae –  5.11.0.1009.7
linux-image-virtual –  5.11.0.18.19

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References

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