USN-5003-1: Linux kernel vulnerabilities

23 June 2021

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-dell300x - Linux kernel for Dell 300x platforms
  • 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
  • linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

Norbert Slusarek discovered a race condition in the CAN BCM networking
protocol of the Linux kernel leading to multiple use-after-free
vulnerabilities. A local attacker could use this issue to execute arbitrary
code. (CVE-2021-3609)

It was discovered that the eBPF implementation in the Linux kernel did not
properly track bounds information for 32 bit registers when performing div
and mod operations. A local attacker could use this to possibly execute
arbitrary code. (CVE-2021-3600)

Or Cohen discovered that the SCTP implementation in the Linux kernel
contained a race condition in some situations, leading to a use-after-free
condition. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-23133)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 18.04
Ubuntu 16.04
Ubuntu 14.04

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.