Issued:

2017-03-02

Updated:

2017-03-02

RHSA-2017:0396 - Important: qemu-kvm security and bug fix update

Synopsis

Important: qemu-kvm security and bug fix update

Type/Severity

Security Advisory Important

Topic

An update for qemu-kvm is now available for Red Hat Enterprise Linux 7.

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.

Description

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):

• Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA emulator support is vulnerable to an out-of-bounds access issue. It could occur while copying VGA data via bitblt copy in backward mode. A privileged user inside a guest could use this flaw to crash the QEMU process resulting in DoS or potentially execute arbitrary code on the host with privileges of QEMU process on the host. (CVE-2017-2615)

• Quick emulator (QEMU) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process. (CVE-2017-2620)

Red Hat would like to thank Wjjzhang (Tencent.com Inc.) and Li Qiang (360.cn Inc.) for reporting CVE-2017-2615.

Bug Fix(es):

• When using the virtio-blk driver on a guest virtual machine with no space on the virtual hard drive, the guest terminated unexpectedly with a "block I/O error in device" message and the qemu-kvm process exited with a segmentation fault. This update fixes how the system_reset QEMU signal is handled in the above scenario. As a result, if a guest crashes due to no space left on the device, qemu-kvm continues running and the guest can be reset as expected. (BZ#1420049)

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.

Affected Products

Updated Packages

• qemu-kvm-1.5.3-126.el7_3.5.src.rpm
• qemu-img-1.5.3-126.el7_3.5.x86_64.rpm
• qemu-kvm-debuginfo-1.5.3-126.el7_3.5.x86_64.rpm
• qemu-kvm-common-1.5.3-126.el7_3.5.x86_64.rpm
• qemu-kvm-tools-1.5.3-126.el7_3.5.x86_64.rpm
• qemu-img-1.5.3-126.el7_3.5.ppc64.rpm
• qemu-img-1.5.3-126.el7_3.5.ppc64le.rpm
• qemu-kvm-1.5.3-126.el7_3.5.x86_64.rpm
• qemu-kvm-debuginfo-1.5.3-126.el7_3.5.ppc64le.rpm
• qemu-kvm-debuginfo-1.5.3-126.el7_3.5.ppc64.rpm

Fixes

• This content is not included.BZ - 1418200
• This content is not included.BZ - 1420049
• This content is not included.BZ - 1420428
• This content is not included.BZ - 1420484

CVEs

• CVE-2017-2615
• CVE-2017-2620

References

• https://access.redhat.com/security/updates/classification/#important

Additional information

• The Red Hat security contact is This content is not included.secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.
• Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.