RHSA-2018:0816 - Security Advisory

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 Low. 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):

• Qemu: vga: OOB read access during display update (CVE-2017-13672)
• Qemu: Slirp: use-after-free when sending response (CVE-2017-13711)
• Qemu: memory exhaustion through framebuffer update request message in VNC server (CVE-2017-15124)
• Qemu: I/O: potential memory exhaustion via websock connection to VNC (CVE-2017-15268)
• Qemu: Out-of-bounds read in vga_draw_text routine (CVE-2018-5683)

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 David Buchanan for reporting CVE-2017-13672; Wjjzhang (Tencent.com) for reporting CVE-2017-13711; and Jiang Xin and Lin ZheCheng for reporting CVE-2018-5683. The CVE-2017-15124 issue was discovered by Daniel Berrange (Red Hat).

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.5 Release Notes linked from the References section.

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

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64

Fixes

• BZ - 1411490 - [RFE] Kernel address space layout randomization [KASLR] support (qemu-kvm)
• BZ - 1417864 - Qemu-kvm starts with unspecified port
• BZ - 1435352 - qemu started with "-vnc none,..." doesn't support any VNC authentication
• BZ - 1450396 - Add support for AMD EPYC processors
• BZ - 1455451 - VM with pty based serial console hangs if PTS buffer is full
• BZ - 1459725 - Prevent qemu-img resize from causing "Active L1 table too large"
• BZ - 1460872 - Aborted(core dumped) when booting guest with "-netdev tap....vhost=on,queues=32"
• BZ - 1461672 - qemu-img core dumped when create external snapshot through ssh protocol without specifying image size
• BZ - 1470244 - reboot leads to shutoff of qemu-kvm-vm if i6300esb-watchdog set to poweroff
• BZ - 1473536 - Hangs in serial console under qemu
• BZ - 1476641 - ui/vnc_keysym.h is very out of date and does not correctly support many Eastern European keyboards
• BZ - 1486400 - CVE-2017-13711 Qemu: Slirp: use-after-free when sending response
• BZ - 1486560 - CVE-2017-13672 Qemu: vga: OOB read access during display update
• BZ - 1491434 - KVM leaks file descriptors when attaching and detaching virtio-scsi block devices
• BZ - 1492559 - virtio-blk mutiwrite merge causes too big IO
• BZ - 1494181 - Backport vGPU support to qemu-kvm
• BZ - 1496879 - CVE-2017-15268 Qemu: I/O: potential memory exhaustion via websock connection to VNC
• BZ - 1511802 - Regression in QEMU handling for sub-page MMIO BARs for vfio-pci devices
• BZ - 1520793 - Do not build non-x86_64 subpackages
• BZ - 1525195 - CVE-2017-15124 Qemu: memory exhaustion through framebuffer update request message in VNC server
• BZ - 1530356 - CVE-2018-5683 Qemu: Out-of-bounds read in vga_draw_text routine
• BZ - 1536883 - [abrt] [faf] qemu-kvm: unknown function(): /usr/libexec/qemu-kvm killed by 6
• BZ - 1538866 - qemu will coredump after executing info qtree

CVEs

• CVE-2017-13672
• CVE-2017-13711
• CVE-2017-15124
• CVE-2017-15268
• CVE-2018-5683

References

• https://access.redhat.com/security/updates/classification/#low
• https://access.redhat.com/documentation/en-US/red_hat_enterprise_linux/7/html/7.5_release_notes/index.html