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

USN-4947-1: Linux kernel (OEM) vulnerabilities

==========================================================================
Ubuntu Security Notice USN-4947-1
May 11, 2021

linux-oem-5.6 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-5.6: Linux kernel for OEM systems

Details:

Kiyin (尹亮) discovered that the x25 implementation in the Linux kernel
contained overflows when handling addresses from user space. A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2020-35519)

It was discovered that the fastrpc driver in the Linux kernel did not
prevent user space applications from sending kernel RPC messages. A local
attacker could possibly use this to gain elevated privileges.
(CVE-2021-28375)

It was discovered that the TIPC protocol implementation in the Linux kernel
did not properly validate passed encryption key sizes. A local attacker
could use this to cause a denial of service (system crash).
(CVE-2021-29646)

It was discovered that a race condition existed in the netfilter subsystem
of the Linux kernel when replacing tables. A local attacker could use this
to cause a denial of service (system crash). (CVE-2021-29650)

Arnd Bergmann discovered that the video4linux subsystem in the Linux kernel
did not properly deallocate memory in some situations. A local attacker
could use this to cause a denial of service (memory exhaustion).
(CVE-2021-30002)

Update instructions:

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

Ubuntu 20.04 LTS:
linux-image-5.6.0-1056-oem 5.6.0-1056.60
linux-image-oem-20.04 5.6.0.1056.52

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-4947-1
CVE-2020-35519, CVE-2021-28375, CVE-2021-29646, CVE-2021-29650,
CVE-2021-30002

Package Information:
  https://launchpad.net/ubuntu/+source/linux-oem-5.6/5.6.0-1056.60