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

USN-4983-1: Linux kernel (OEM) vulnerabilities

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Ubuntu Security Notice USN-4983-1
June 03, 2021

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:

Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel
did not properly enforce limits for pointer operations. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-33200)

Piotr Krysiuk and Benedict Schlueter discovered that the eBPF
implementation in the Linux kernel performed out of bounds speculation on
pointer arithmetic. A local attacker could use this to expose sensitive
information. (CVE-2021-29155)

Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel
did not properly prevent speculative loads in certain situations. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2021-31829)

Reiji Watanabe discovered that the KVM VMX implementation in the Linux
kernel did not properly prevent user space from tampering with an array
index value, leading to a potential out-of-bounds write. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-3501)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.10.0-1029-oem 5.10.0-1029.30
linux-image-oem-20.04 5.10.0.1029.30
linux-image-oem-20.04b 5.10.0.1029.30

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-4983-1
CVE-2021-29155, CVE-2021-31829, CVE-2021-33200, CVE-2021-3501

Package Information:
  https://launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1029.30