1. Ubuntu Security Notices
  2. USN-5484-1

USN-5484-1: Linux kernel vulnerabilities

Publication date

16 June 2022

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

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)

It was discovered that a race condition existed in the network scheduling
subsystem of the Linux kernel, leading to a use-after-free vulnerability. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2021-39713)

It was discovered that some Intel processors did not completely perform
cleanup actions on multi-core shared buffers. A local attacker could
possibly use this to expose sensitive information. (CVE-2022-21123)

It was discovered that some Intel processors did not completely perform
cleanup actions on...

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)

It was discovered that a race condition existed in the network scheduling
subsystem of the Linux kernel, leading to a use-after-free vulnerability. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2021-39713)

It was discovered that some Intel processors did not completely perform
cleanup actions on multi-core shared buffers. A local attacker could
possibly use this to expose sensitive information. (CVE-2022-21123)

It was discovered that some Intel processors did not completely perform
cleanup actions on microarchitectural fill buffers. A local attacker could
possibly use this to expose sensitive information. (CVE-2022-21125)

It was discovered that some Intel processors did not properly perform
cleanup during specific special register write operations. A local attacker
could possibly use this to expose sensitive information. (CVE-2022-21166)

Update instructions

Please note that fully mitigating processor vulnerabilities requires corresponding processor microcode/firmware updates. 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
14.04 trusty linux-image-virtual –  3.13.0.190.199  
linux-image-3.13.0-190-generic –  3.13.0-190.241  
linux-image-server –  3.13.0.190.199  
linux-image-3.13.0-190-lowlatency –  3.13.0-190.241  
linux-image-generic –  3.13.0.190.199  
linux-image-lowlatency –  3.13.0.190.199  

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References

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