A Linux kernel (Raspberry Pi) security update has been released for Ubuntu Linux 18.04 LTS.

USN-5073-3: Linux kernel (Raspberry Pi) vulnerabilities

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Ubuntu Security Notice USN-5073-3
September 22, 2021

linux-raspi2 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-raspi2: Linux kernel for Raspberry Pi (V8) systems

Details:

Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol
implementation in the Linux kernel did not properly initialize memory in
some situations. A local attacker could use this to expose sensitive
information (kernel memory). (CVE-2021-34693)

Murray McAllister discovered that the joystick device interface in the
Linux kernel did not properly validate data passed via an ioctl(). A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code on systems with a joystick device
registered. (CVE-2021-3612)

It was discovered that the Virtio console implementation in the Linux
kernel did not properly validate input lengths in some situations. A local
attacker could possibly use this to cause a denial of service (system
crash). (CVE-2021-38160)

Update instructions:

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

Ubuntu 18.04 LTS:
linux-image-4.15.0-1095-raspi2 4.15.0-1095.101
linux-image-raspi2 4.15.0.1095.93

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-5073-3
  https://ubuntu.com/security/notices/USN-5073-1
CVE-2021-34693, CVE-2021-3612, CVE-2021-38160

Package Information:
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1095.101