1. Ubuntu Security Notices
  2. USN-5016-1

USN-5016-1: Linux kernel vulnerabilities

Publication date

20 July 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-aws-5.8 - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-5.8 - Linux kernel for Microsoft Azure cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-5.8 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe-5.8 - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-oracle-5.8 - Linux kernel for Oracle Cloud systems
  • linux-raspi - Linux kernel for Raspberry Pi (V8) systems

Details

It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2021-33909)

Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the
nfc implementation in the Linux kernel. A privileged local attacker could
use this issue to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-23134)

It was discovered that a race condition in the kernel Bluetooth subsystem
could lead to use-after-free of slab objects. An attacker could use this
issue to possibly execute arbitrary code. (CVE-2021-32399)

It was discovered that a use-after-free existed in the Bluetooth HCI driver
of the Linux...

It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code. (CVE-2021-33909)

Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the
nfc implementation in the Linux kernel. A privileged local attacker could
use this issue to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-23134)

It was discovered that a race condition in the kernel Bluetooth subsystem
could lead to use-after-free of slab objects. An attacker could use this
issue to possibly execute arbitrary code. (CVE-2021-32399)

It was discovered that a use-after-free existed in the Bluetooth HCI driver
of the Linux kernel. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-33034)

It was discovered that an out-of-bounds (OOB) memory access flaw existed in
the f2fs module of the Linux kernel. A local attacker could use this issue
to cause a denial of service (system crash). (CVE-2021-3506)

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
20.10 groovy linux-image-generic –  5.8.0.63.69
linux-image-virtual –  5.8.0.63.69
linux-image-generic-64k –  5.8.0.63.69
linux-image-5.8.0-1033-kvm –  5.8.0-1033.36
linux-image-aws –  5.8.0.1041.43
linux-image-5.8.0-63-generic-64k –  5.8.0-63.71
linux-image-5.8.0-1032-raspi –  5.8.0-1032.35
linux-image-5.8.0-63-generic-lpae –  5.8.0-63.71
linux-image-5.8.0-1032-raspi-nolpae –  5.8.0-1032.35
linux-image-azure –  5.8.0.1039.40
linux-image-raspi-nolpae –  5.8.0.1032.34
linux-image-5.8.0-63-lowlatency –  5.8.0-63.71
linux-image-oem-20.04 –  5.8.0.63.69
linux-image-gke –  5.8.0.1038.38
linux-image-kvm –  5.8.0.1033.36
linux-image-5.8.0-1037-oracle –  5.8.0-1037.38
linux-image-5.8.0-1039-azure –  5.8.0-1039.42
linux-image-5.8.0-63-generic –  5.8.0-63.71
linux-image-gcp –  5.8.0.1038.38
linux-image-oracle –  5.8.0.1037.36
linux-image-5.8.0-1038-gcp –  5.8.0-1038.40
linux-image-raspi –  5.8.0.1032.34
linux-image-5.8.0-1041-aws –  5.8.0-1041.43
linux-image-generic-lpae –  5.8.0.63.69
linux-image-lowlatency –  5.8.0.63.69
20.04 focal linux-image-5.8.0-1038-gcp –  5.8.0-1038.40~20.04.1
linux-image-aws –  5.8.0.1041.43~20.04.13
linux-image-5.8.0-63-generic-64k –  5.8.0-63.71~20.04.1
linux-image-lowlatency-hwe-20.04 –  5.8.0.63.71~20.04.45
linux-image-5.8.0-63-lowlatency –  5.8.0-63.71~20.04.1
linux-image-generic-hwe-20.04 –  5.8.0.63.71~20.04.45
linux-image-azure –  5.8.0.1039.42~20.04.11
linux-image-5.8.0-1039-azure –  5.8.0-1039.42~20.04.1
linux-image-5.8.0-1037-oracle –  5.8.0-1037.38~20.04.1
linux-image-virtual-hwe-20.04 –  5.8.0.63.71~20.04.45
linux-image-5.8.0-63-generic –  5.8.0-63.71~20.04.1
linux-image-gcp –  5.8.0.1038.40~20.04.13
linux-image-5.8.0-63-generic-lpae –  5.8.0-63.71~20.04.1
linux-image-generic-64k-hwe-20.04 –  5.8.0.63.71~20.04.45
linux-image-oracle –  5.8.0.1037.38~20.04.13
linux-image-generic-lpae-hwe-20.04 –  5.8.0.63.71~20.04.45
linux-image-5.8.0-1041-aws –  5.8.0-1041.43~20.04.1

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References

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