USN-5484-1: Linux kernel vulnerabilities

16 June 2022

Several security issues were fixed in the Linux kernel.

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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 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)

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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.

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Update instructions

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

Ubuntu 14.04

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.

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.

References

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