-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2019.4286
                           linux security update
                             14 November 2019

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           linux kernel
Publisher:         Debian
Operating System:  Debian GNU/Linux 9
                   Debian GNU/Linux 10
Impact/Access:     Root Compromise        -- Existing Account
                   Access Privileged Data -- Existing Account
                   Denial of Service      -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2019-11135 CVE-2019-0155 CVE-2019-0154
                   CVE-2018-12207  

Reference:         ASB-2019.0322
                   ASB-2019.0313
                   ESB-2019.4274
                   ESB-2019.4273
                   ESB-2019.4271

Original Bulletin: 
   http://www.debian.org/security/2019/dsa-4564

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

- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

- - -------------------------------------------------------------------------
Debian Security Advisory DSA-4564-1                   security@debian.org
https://www.debian.org/security/                            Ben Hutchings
November 12, 2019                     https://www.debian.org/security/faq
- - -------------------------------------------------------------------------

Package        : linux
CVE ID         : CVE-2018-12207 CVE-2019-0154 CVE-2019-0155 CVE-2019-11135

Several vulnerabilities have been discovered in the Linux kernel that
may lead to a privilege escalation, denial of service, or information
leak.

CVE-2018-12207

    It was discovered that on Intel CPUs supporting hardware
    virtualisation with Extended Page Tables (EPT), a guest VM may
    manipulate the memory management hardware to cause a Machine Check
    Error (MCE) and denial of service (hang or crash).

    The guest triggers this error by changing page tables without a
    TLB flush, so that both 4 KB and 2 MB entries for the same virtual
    address are loaded into the instruction TLB (iTLB).  This update
    implements a mitigation in KVM that prevents guest VMs from
    loading 2 MB entries into the iTLB.  This will reduce performance
    of guest VMs.

    Further information on the mitigation can be found at
    <https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/multihit.html>
    or in the linux-doc-4.9 or linux-doc-4.19 package.

    A qemu update adding support for the PSCHANGE_MC_NO feature, which
    allows to disable iTLB Multihit mitigations in nested hypervisors
    will be provided via DSA 4566-1.

    Intel's explanation of the issue can be found at
    <https://software.intel.com/security-software-guidance/insights/deep-dive-machine-check-error-avoidance-page-size-change-0>.

CVE-2019-0154

    Intel discovered that on their 8th and 9th generation GPUs,
    reading certain registers while the GPU is in a low-power state
    can cause a system hang.  A local user permitted to use the GPU
    can use this for denial of service.

    This update mitigates the issue through changes to the i915
    driver.

    The affected chips (gen8 and gen9) are listed at
    <https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units#Gen8>.

CVE-2019-0155

    Intel discovered that their 9th generation and newer GPUs are
    missing a security check in the Blitter Command Streamer (BCS).  A
    local user permitted to use the GPU could use this to access any
    memory that the GPU has access to, which could result in a denial
    of service (memory corruption or crash), a leak of sensitive
    information, or privilege escalation.

    This update mitigates the issue by adding the security check to
    the i915 driver.

    The affected chips (gen9 onward) are listed at
    <https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units#Gen9>.

CVE-2019-11135

    It was discovered that on Intel CPUs supporting transactional
    memory (TSX), a transaction that is going to be aborted may
    continue to execute speculatively, reading sensitive data from
    internal buffers and leaking it through dependent operations.
    Intel calls this "TSX Asynchronous Abort" (TAA).

    For CPUs affected by the previously published Microarchitectural
    Data Sampling (MDS) issues (CVE-2018-12126, CVE-2018-12127,
    CVE-2018-12130, CVE-2019-11091), the existing mitigation also
    mitigates this issue.

    For processors that are vulnerable to TAA but not MDS, this update
    disables TSX by default.  This mitigation requires updated CPU
    microcode.  An updated intel-microcode package (only available in
    Debian non-free) will be provided via DSA 4565-1.  The updated CPU
    microcode may also be available as part of a system firmware
    ("BIOS") update.

    Further information on the mitigation can be found at
    <https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html>
    or in the linux-doc-4.9 or linux-doc-4.19 package.

    Intel's explanation of the issue can be found at
    <https://software.intel.com/security-software-guidance/insights/deep-dive-intel-transactional-synchronization-extensions-intel-tsx-asynchronous-abort>.

For the oldstable distribution (stretch), these problems have been fixed
in version 4.9.189-3+deb9u2.

For the stable distribution (buster), these problems have been fixed in
version 4.19.67-2+deb10u2.

We recommend that you upgrade your linux packages.

For the detailed security status of linux please refer to its security
tracker page at:
https://security-tracker.debian.org/tracker/linux

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/

Mailing list: debian-security-announce@lists.debian.org
- -----BEGIN PGP SIGNATURE-----
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=YZWL
- -----END PGP SIGNATURE-----

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        https://www.auscert.org.au/bulletins/

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=6Mk1
-----END PGP SIGNATURE-----