1. Ubuntu Security Notices
  2. USN-5465-1

USN-5465-1: Linux kernel vulnerabilities

Publication date

8 June 2022

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-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

It was discovered that the Linux kernel did not properly restrict access to
the kernel debugger when booted in secure boot environments. A privileged
attacker could use this to bypass UEFI Secure Boot restrictions.
(CVE-2022-21499)

Aaron Adams discovered that the netfilter subsystem in the Linux kernel did
not properly handle the removal of stateful expressions in some situations,
leading to a use-after-free vulnerability. A local attacker could use this
to cause a denial of service (system crash) or execute arbitrary code.
(CVE-2022-1966)

Jann Horn discovered that the Linux kernel did not properly enforce seccomp
restrictions in some situations. A local attacker could use this to bypass
intended seccomp sandbox restrictions. (CVE-2022-30594)

It was discovered that the Linux kernel did not properly restrict access to
the kernel debugger when booted in secure boot environments. A privileged
attacker could use this to bypass UEFI Secure Boot restrictions.
(CVE-2022-21499)

Aaron Adams discovered that the netfilter subsystem in the Linux kernel did
not properly handle the removal of stateful expressions in some situations,
leading to a use-after-free vulnerability. A local attacker could use this
to cause a denial of service (system crash) or execute arbitrary code.
(CVE-2022-1966)

Jann Horn discovered that the Linux kernel did not properly enforce seccomp
restrictions in some situations. A local attacker could use this to bypass
intended seccomp sandbox restrictions. (CVE-2022-30594)

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
16.04 xenial linux-image-virtual –  4.4.0.227.233  
linux-image-generic –  4.4.0.227.233  
linux-image-4.4.0-227-lowlatency –  4.4.0-227.261  
linux-image-aws –  4.4.0.1143.147  
linux-image-4.4.0-227-generic –  4.4.0-227.261  
linux-image-4.4.0-1143-aws –  4.4.0-1143.158  
linux-image-4.4.0-1108-kvm –  4.4.0-1108.118  
linux-image-kvm –  4.4.0.1108.105  
linux-image-lowlatency –  4.4.0.227.233  
14.04 trusty linux-image-4.4.0-227-lowlatency –  4.4.0-227.261~14.04.1  
linux-image-generic-lts-xenial –  4.4.0.227.197  
linux-image-4.4.0-227-generic –  4.4.0-227.261~14.04.1  
linux-image-4.4.0-1107-aws –  4.4.0-1107.113  
linux-image-lowlatency-lts-xenial –  4.4.0.227.197  
linux-image-aws –  4.4.0.1107.104  
linux-image-virtual-lts-xenial –  4.4.0.227.197  

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References

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