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
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Red Hat Enterprise Linux Server 7 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.6 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.5 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.4 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.3 x86_64
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Red Hat Enterprise Linux Server - AUS 7.6 x86_64
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Red Hat Enterprise Linux Workstation 7 x86_64
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Red Hat Enterprise Linux Desktop 7 x86_64
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Red Hat Enterprise Linux for Power, big endian 7 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
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Red Hat Enterprise Linux for Scientific Computing 7 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
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Red Hat Enterprise Linux Server - AUS 7.4 x86_64
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Red Hat Enterprise Linux Server - AUS 7.3 x86_64
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Red Hat Enterprise Linux for Power, little endian 7 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
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Red Hat Enterprise Linux Server - TUS 7.6 x86_64
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Red Hat Enterprise Linux Server - TUS 7.3 x86_64
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.3 ppc64le
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64
Fixes
- BZ - 1418200 - CVE-2017-2615 Qemu: display: cirrus: oob access while doing bitblt copy backward mode
- BZ - 1420049 - system_reset should clear pending request for error (virtio-blk)
- BZ - 1420428 - Remove dependencies required by spice on ppc64le
- BZ - 1420484 - CVE-2017-2620 Qemu: display: cirrus: potential arbitrary code execution via cirrus_bitblt_cputovideo
CVEs
References
Vulmon