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             AUSCERT External Security Bulletin Redistribution

                 USN-4678-1: Linux kernel vulnerabilities
                              7 January 2021


        AusCERT Security Bulletin Summary

Product:           kernel
Publisher:         Ubuntu
Operating System:  Ubuntu
                   Linux variants
Impact/Access:     Increased Privileges     -- Existing Account
                   Access Confidential Data -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-29534 CVE-2020-12912 

Original Bulletin: 

Comment: This advisory references vulnerabilities in the Linux kernel that 
         also affect distributions other than Ubuntu. It is recommended that
         administrators running Linux check for an updated version of the 
         kernel for their system.

- --------------------------BEGIN INCLUDED TEXT--------------------

USN-4678-1: Linux kernel vulnerabilities
06 January 2021

Several security issues were fixed in the Linux kernel.

  o Ubuntu 20.10
  o Ubuntu 20.04 LTS


  o linux - Linux kernel
  o linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  o linux-azure - Linux kernel for Microsoft Azure Cloud systems
  o linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  o linux-hwe-5.8 - Linux hardware enablement (HWE) kernel
  o linux-kvm - Linux kernel for cloud environments
  o linux-oracle - Linux kernel for Oracle Cloud systems
  o linux-raspi - Linux kernel for Raspberry Pi (V8) systems


It was discovered that the AMD Running Average Power Limit (RAPL) driver in
the Linux kernel did not properly restrict access to power data. A local
attacker could possibly use this to expose sensitive information.

Jann Horn discovered that the io_uring subsystem in the Linux kernel did
not properly perform reference counting in some situations. A local
attacker could use this to expose sensitive information or possibly
escalate privileges. (CVE-2020-29534)

Update instructions

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

Ubuntu 20.10

  o linux-image-5.8.0-1011-raspi - 5.8.0-1011.14
  o linux-image-5.8.0-1011-raspi-nolpae - 5.8.0-1011.14
  o linux-image-5.8.0-1014-kvm - 5.8.0-1014.15
  o linux-image-5.8.0-1014-oracle - 5.8.0-1014.14
  o linux-image-5.8.0-1015-gcp - 5.8.0-1015.15
  o linux-image-5.8.0-1016-azure - 5.8.0-1016.17
  o linux-image-5.8.0-1017-aws - 5.8.0-1017.18
  o linux-image-5.8.0-34-generic - 5.8.0-34.37
  o linux-image-5.8.0-34-generic-64k - 5.8.0-34.37
  o linux-image-5.8.0-34-generic-lpae - 5.8.0-34.37
  o linux-image-5.8.0-34-lowlatency - 5.8.0-34.37
  o linux-image-aws -
  o linux-image-azure -
  o linux-image-gcp -
  o linux-image-generic -
  o linux-image-generic-64k -
  o linux-image-generic-lpae -
  o linux-image-gke -
  o linux-image-kvm -
  o linux-image-lowlatency -
  o linux-image-oracle -
  o linux-image-raspi -
  o linux-image-raspi-nolpae -
  o linux-image-virtual -

Ubuntu 20.04

  o linux-image-5.8.0-34-generic - 5.8.0-34.37~20.04.2
  o linux-image-5.8.0-34-generic-lpae - 5.8.0-34.37~20.04.2
  o linux-image-5.8.0-34-lowlatency - 5.8.0-34.37~20.04.2
  o linux-image-generic-hwe-20.04 -
  o linux-image-generic-lpae-hwe-20.04 -
  o linux-image-lowlatency-hwe-20.04 -
  o linux-image-virtual-hwe-20.04 -

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.


  o CVE-2020-12912
  o CVE-2020-29534

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