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Red Hat: RHSA-2018:1661 Important: qemu-kvm Cache Attack Risk

red hat
Calendar Grey May 22, 2018
Scroller Redhat
An essential patch has been released for qemu-kvm that addresses a significant vulnerability affecting several versions of Red Hat Enterprise Linux, resulting in notable security implications.
An update for qemu-kvm is now available for Red Hat Enterprise Linux 7.2 Advanced Update Support, Red Hat Enterprise Linux 7.2 Telco Extended Update Support, and Red Hat Enterprise...

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

After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.

Summary

Kernel-based Virtual Machine (KVM) is a full virtualization solution for Linux on a variety of architectures. The qemu-kvm packages provide the user-space component for running virtual machines that use KVM.
Security Fix(es):
* 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)
Note: This is the qemu-kvm side of the CVE-2018-3639 mitigation.
Red Hat would like to thank Ken Johnson (Microsoft Security Response Center) and Jann Horn (Google Project Zero) for reporting this issue.

Topics%20covered

Topics Covered

security advisory Red Hat security fix important KVM qemu-kvm cache attack

References

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

Package List

Red Hat Enterprise Linux Server AUS (v. 7.2):
Source: qemu-kvm-1.5.3-105.el7_2.17.src.rpm
x86_64: libcacard-1.5.3-105.el7_2.17.i686.rpm libcacard-1.5.3-105.el7_2.17.x86_64.rpm qemu-img-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-common-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-debuginfo-1.5.3-105.el7_2.17.i686.rpm qemu-kvm-debuginfo-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-tools-1.5.3-105.el7_2.17.x86_64.rpm
Red Hat Enterprise Linux Server E4S (v. 7.2):
Source: qemu-kvm-1.5.3-105.el7_2.17.src.rpm
ppc64le: qemu-img-1.5.3-105.el7_2.17.ppc64le.rpm qemu-kvm-debuginfo-1.5.3-105.el7_2.17.ppc64le.rpm
x86_64: libcacard-1.5.3-105.el7_2.17.i686.rpm libcacard-1.5.3-105.el7_2.17.x86_64.rpm qemu-img-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-common-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-debuginfo-1.5.3-105.el7_2.17.i686.rpm qemu-kvm-debuginfo-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-tools-1.5.3-105.el7_2.17.x86_64.rpm
Red Hat Enterprise Linux Server TUS (v. 7.2):
Source: qemu-kvm-1.5.3-105.el7_2.17.src.rpm
x86_64: libcacard-1.5.3-105.el7_2.17.i686.rpm libcacard-1.5.3-105.el7_2.17.x86_64.rpm qemu-img-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-1.5.3-105.el7_2.17.x86_64.rpm qemu-kvm-common-1.5.3-105.el7_2.17.x86_64.rpm

Read the Full Advisory


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2018:1661-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2018:1661
Issue date: 2018-05-21

Topic

An update for qemu-kvm is now available for Red Hat Enterprise Linux 7.2Advanced Update Support, Red Hat Enterprise Linux 7.2 Telco Extended UpdateSupport, and Red Hat Enterprise Linux 7.2 Update Services for SAPSolutions.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory Red Hat security fix important KVM qemu-kvm cache attack

Relevant Releases Architectures

Red Hat Enterprise Linux Server AUS (v. 7.2) - x86_64

Red Hat Enterprise Linux Server E4S (v. 7.2) - ppc64le, x86_64

Red Hat Enterprise Linux Server Optional AUS (v. 7.2) - x86_64

Red Hat Enterprise Linux Server Optional E4S (v. 7.2) - ppc64le, x86_64

Red Hat Enterprise Linux Server Optional TUS (v. 7.2) - x86_64

Red Hat Enterprise Linux Server TUS (v. 7.2) - x86_64

Bugs Fixed

1566890 - CVE-2018-3639 hw: cpu: speculative store bypass

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