[LSN-0073-1] Linux kernel vulnerability

[benjamin.romer at canonical.com]

Linux kernel vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

-   Ubuntu 18.04 LTS
-   Ubuntu 20.04 LTS

Summary

Several security issues were fixed in the kernel.

Software Description

-   linux - Linux kernel
-   linux-aws - Linux kernel for Amazon Web Services (AWS) systems
-   linux-azure - Linux kernel for Microsoft Azure Cloud systems
-   linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
-   linux-oem - Linux kernel for OEM systems

Details

Andy Nguyen discovered that the Bluetooth L2CAP implementation in the
Linux kernel contained a type-confusion error. A physically proximate
remote attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2020-12351)

Andy Nguyen discovered that the Bluetooth A2MP implementation in the
Linux kernel did not properly initialize memory in some situations. A
physically proximate remote attacker could use this to expose sensitive
information (kernel memory). (CVE-2020-12352)

Andy Nguyen discovered that the Bluetooth HCI event packet parser in the
Linux kernel did not properly handle event advertisements of certain
sizes, leading to a heap-based buffer overflow. A physically proximate
remote attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2020-24490)


Update instructions

The problem can be corrected by updating your kernel livepatch to the
following versions:

Ubuntu 18.04 LTS
    aws - 73.1
    generic - 73.1
    lowlatency - 73.1
    oem - 73.1

Ubuntu 20.04 LTS
    aws - 73.1
    azure - 73.1
    gcp - 73.1
    generic - 73.1
    lowlatency - 73.1


Support Information

Kernels older than the levels listed below do not receive livepatch
updates. If you are running a kernel version earlier than the one listed
below, please upgrade your kernel as soon as possible.

Ubuntu 18.04 LTS
    linux-aws - 4.15.0-1054
    linux-azure - 5.0.0-1025
    linux-gcp - 5.0.0-1025
    linux-oem - 4.15.0-1063
    linux - 4.15.0-69

Ubuntu 20.04 LTS
    linux-aws - 5.4.0-1009
    linux-azure - 5.4.0-1010
    linux-gcp - 5.4.0-1009
    linux-oem - 5.4.0-26
    linux - 5.4.0-26

Ubuntu 16.04 LTS
    linux-aws - 4.4.0-1098
    linux-azure - 4.15.0-1063
    linux-hwe - 4.15.0-69
    linux - 4.4.0-168

Ubuntu 14.04 ESM
    linux-lts-xenial - 4.4.0-168


References

-   CVE-2020-12351
-   CVE-2020-12352
-   CVE-2020-24490