A Linux kernel security update has been released for Ubuntu Linux 20.04 LTS.

USN-5207-1: Linux kernel (OEM) vulnerabilities

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Ubuntu Security Notice USN-5207-1
January 05, 2022

linux-oem-5.10 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-oem-5.10: Linux kernel for OEM systems

Details:

Nadav Amit discovered that the hugetlb implementation in the Linux kernel
did not perform TLB flushes under certain conditions. A local attacker
could use this to leak or alter data from other processes that use huge
pages. (CVE-2021-4002)

It was discovered that the eBPF implementation in the Linux kernel
contained a race condition around read-only maps. A privileged attacker
could use this to modify read-only maps. (CVE-2021-4001)

Luo Likang discovered that the FireDTV Firewire driver in the Linux kernel
did not properly perform bounds checking in some situations. A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2021-42739)

It was discovered that the TIPC Protocol implementation in the Linux kernel
did not properly validate MSG_CRYPTO messages in some situations. An
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2021-43267)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.10.0-1053-oem 5.10.0-1053.55
linux-image-oem-20.04 5.10.0.1053.55
linux-image-oem-20.04b 5.10.0.1053.55

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:
  https://ubuntu.com/security/notices/USN-5207-1
CVE-2021-4001, CVE-2021-4002, CVE-2021-42739, CVE-2021-43267

Package Information:
  https://launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1053.55r