[RHSA-2018:2394-01] Important: kernel security update

Tue Aug 14 20:18:18 UTC 2018

An update for kernel is now available for Red Hat Enterprise Linux 6.4
Advanced Update Support.

Red Hat Product Security has rated this update as having a security impact
of Important. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available for each vulnerability
from the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Server AUS (v. 6.4) - noarch, x86_64
Red Hat Enterprise Linux Server Optional AUS (v. 6.4) - x86_64

3. Description:

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security Fix(es):

* Modern operating systems implement virtualization of physical memory to
efficiently use available system resources and provide inter-domain
protection through access control and isolation. The L1TF issue was found
in the way the x86 microprocessor designs have implemented speculative
execution of instructions (a commonly used performance optimisation) in
combination with handling of page-faults caused by terminated virtual to
physical address resolving process. As a result, an unprivileged attacker
could use this flaw to read privileged memory of the kernel or other
processes and/or cross guest/host boundaries to read host memory by
conducting targeted cache side-channel attacks. (CVE-2018-3620,
CVE-2018-3646)

* An industry-wide issue was found in the way many modern microprocessor
designs have implemented speculative execution of Load & Store instructions
(a commonly used performance optimization). It relies on the presence of a
precisely-defined instruction sequence in the privileged code as well as
the fact that memory read from address to which a recent memory write has
occurred may see an older value and subsequently cause an update into the
microprocessor's data cache even for speculatively executed instructions
that never actually commit (retire). As a result, an unprivileged attacker
could use this flaw to read privileged memory by conducting targeted cache
side-channel attacks. (CVE-2018-3639)

* kernel: kvm: vmx: host GDT limit corruption (CVE-2018-10901)

For more details about the security issue(s), including the impact, a CVSS
score, and other related information, refer to the CVE page(s) listed in
the References section.

Red Hat would like to thank Intel OSSIRT (Intel.com) for reporting
CVE-2018-3620 and CVE-2018-3646; Ken Johnson (Microsoft Security Response
Center) and Jann Horn (Google Project Zero) for reporting CVE-2018-3639;
and Vegard Nossum (Oracle Corporation) for reporting CVE-2018-10901.

4. Solution:

For details on how to apply this update, which includes the changes
described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1566890 - CVE-2018-3639 hw: cpu: speculative store bypass
1585005 - CVE-2018-3646 Kernel: hw: cpu: L1 terminal fault (L1TF)
1601849 - CVE-2018-10901 kernel: kvm: vmx: host GDT limit corruption

6. Package List:

Red Hat Enterprise Linux Server AUS (v. 6.4):

Source:
kernel-2.6.32-358.91.4.el6.src.rpm

noarch:
kernel-doc-2.6.32-358.91.4.el6.noarch.rpm
kernel-firmware-2.6.32-358.91.4.el6.noarch.rpm

x86_64:
kernel-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debug-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debug-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debug-devel-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debuginfo-common-x86_64-2.6.32-358.91.4.el6.x86_64.rpm
kernel-devel-2.6.32-358.91.4.el6.x86_64.rpm
kernel-headers-2.6.32-358.91.4.el6.x86_64.rpm
perf-2.6.32-358.91.4.el6.x86_64.rpm
perf-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
python-perf-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm

Red Hat Enterprise Linux Server Optional AUS (v. 6.4):

Source:
kernel-2.6.32-358.91.4.el6.src.rpm

x86_64:
kernel-debug-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
kernel-debuginfo-common-x86_64-2.6.32-358.91.4.el6.x86_64.rpm
perf-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm
python-perf-2.6.32-358.91.4.el6.x86_64.rpm
python-perf-debuginfo-2.6.32-358.91.4.el6.x86_64.rpm

These packages are GPG signed by Red Hat for security.  Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/

7. References:

https://access.redhat.com/security/cve/CVE-2018-3620
https://access.redhat.com/security/cve/CVE-2018-3639
https://access.redhat.com/security/cve/CVE-2018-3646
https://access.redhat.com/security/cve/CVE-2018-10901
https://access.redhat.com/security/updates/classification/#important
https://access.redhat.com/security/vulnerabilities/L1TF
https://access.redhat.com/security/vulnerabilities/ssbd

8. Contact:

The Red Hat security contact is <secalert at redhat.com>. More contact
details at https://access.redhat.com/security/team/contact/

Copyright 2018 Red Hat, Inc.
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