1. Ubuntu Security Notices
  2. USN-5044-1

USN-5044-1: Linux kernel vulnerabilities

Publication date

24 August 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-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-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly handle HCI device initialization failure, leading to a double-free
vulnerability. An attacker could use this to cause a denial of service or
possibly execute arbitrary code. (CVE-2021-3564)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly handle HCI device detach events, leading to a use-after-free
vulnerability. An attacker could use this to cause a denial of service or
possibly execute arbitrary code. (CVE-2021-3573)

It was discovered that the NFC implementation in the Linux kernel did not
properly handle failed connect events leading to a NULL pointer
dereference. A local attacker could use this to cause a denial of service.
(CVE-2021-3587)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly handle HCI device initialization failure, leading to a double-free
vulnerability. An attacker could use this to cause a denial of service or
possibly execute arbitrary code. (CVE-2021-3564)

It was discovered that the bluetooth subsystem in the Linux kernel did not
properly handle HCI device detach events, leading to a use-after-free
vulnerability. An attacker could use this to cause a denial of service or
possibly execute arbitrary code. (CVE-2021-3573)

It was discovered that the NFC implementation in the Linux kernel did not
properly handle failed connect events leading to a NULL pointer
dereference. A local attacker could use this to cause a denial of service.
(CVE-2021-3587)

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-4.15.0-1079-oracle –  4.15.0-1079.87
linux-image-4.15.0-1094-raspi2 –  4.15.0-1094.100
linux-image-4.15.0-1098-kvm –  4.15.0-1098.100
linux-image-4.15.0-1107-gcp –  4.15.0-1107.121
linux-image-4.15.0-1110-aws –  4.15.0-1110.117
linux-image-4.15.0-1111-snapdragon –  4.15.0-1111.120
linux-image-4.15.0-1122-azure –  4.15.0-1122.135
linux-image-4.15.0-154-generic –  4.15.0-154.161
linux-image-4.15.0-154-generic-lpae –  4.15.0-154.161
linux-image-4.15.0-154-lowlatency –  4.15.0-154.161
linux-image-aws-lts-18.04 –  4.15.0.1110.113
linux-image-azure-lts-18.04 –  4.15.0.1122.95
linux-image-gcp-lts-18.04 –  4.15.0.1107.126
linux-image-generic –  4.15.0.154.143
linux-image-generic-lpae –  4.15.0.154.143
linux-image-kvm –  4.15.0.1098.94
linux-image-lowlatency –  4.15.0.154.143
linux-image-oracle-lts-18.04 –  4.15.0.1079.89
linux-image-raspi2 –  4.15.0.1094.92
linux-image-snapdragon –  4.15.0.1111.114
linux-image-virtual –  4.15.0.154.143
16.04 xenial linux-image-4.15.0-1079-oracle –  4.15.0-1079.87~16.04.1  
linux-image-4.15.0-1107-gcp –  4.15.0-1107.121~16.04.1  
linux-image-4.15.0-1110-aws –  4.15.0-1110.117~16.04.1  
linux-image-4.15.0-1122-azure –  4.15.0-1122.135~16.04.1  
linux-image-4.15.0-154-generic –  4.15.0-154.161~16.04.1  
linux-image-4.15.0-154-lowlatency –  4.15.0-154.161~16.04.1  
linux-image-aws-hwe –  4.15.0.1110.101  
linux-image-azure –  4.15.0.1122.113  
linux-image-gcp –  4.15.0.1107.108  
linux-image-generic-hwe-16.04 –  4.15.0.154.148  
linux-image-gke –  4.15.0.1107.108  
linux-image-lowlatency-hwe-16.04 –  4.15.0.154.148  
linux-image-oem –  4.15.0.154.148  
linux-image-oracle –  4.15.0.1079.67  
linux-image-virtual-hwe-16.04 –  4.15.0.154.148  
14.04 trusty linux-image-4.15.0-1122-azure –  4.15.0-1122.135~14.04.1  
linux-image-azure –  4.15.0.1122.95  

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References

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