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             AUSCERT External Security Bulletin Redistribution

                  USN-4031-1: Linux kernel vulnerability
                               25 June 2019


        AusCERT Security Bulletin Summary

Product:           linux kernel
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Access Privileged Data -- Existing Account
                   Denial of Service      -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2019-12817  

Original Bulletin: 

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

USN-4031-1: Linux kernel vulnerability
24 June 2019

linux, linux-hwe vulnerability
A security issue affects these releases of Ubuntu and its derivatives:

  o Ubuntu 19.04
  o Ubuntu 18.10
  o Ubuntu 18.04 LTS


64-Bit PowerPC systems could be made to expose sensitive information.

Software Description

  o linux - Linux kernel
  o linux-hwe - Linux hardware enablement (HWE) kernel


It was discovered that the Linux kernel did not properly separate certain
memory mappings when creating new userspace processes on 64-bit Power (ppc64el)
systems. A local attacker could use this to access memory contents or cause
memory corruption of other processes on the system.

Update instructions

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

Ubuntu 19.04
    linux-image-5.0.0-19-generic - 5.0.0-19.20
    linux-image-generic -
    linux-image-virtual -
Ubuntu 18.10
    linux-image-4.18.0-24-generic - 4.18.0-24.25
    linux-image-generic -
    linux-image-powerpc-e500mc -
    linux-image-powerpc-smp -
    linux-image-powerpc64-emb -
    linux-image-powerpc64-smp -
    linux-image-virtual -
Ubuntu 18.04 LTS
    linux-image-4.18.0-24-generic - 4.18.0-24.25~18.04.1
    linux-image-generic-hwe-18.04 -
    linux-image-virtual-hwe-18.04 -

To update your system, please follow these instructions: https://
wiki.ubuntu.com/Security/Upgrades .

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-2019-12817

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