RHSA-2017:1682 - Security Advisory

Topic

An update for qemu-kvm-rhev is now available for RHEV 3.X Hypervisor and Agents for RHEL-7 and RHEV 4.X RHEV-H and Agents for RHEL-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

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on a variety of architectures. The qemu-kvm-rhev packages provide the user-space component for running virtual machines that use KVM in environments managed by Red Hat products.

Security Fix(es):

• Quick Emulator (QEMU) built with Network Block Device (NBD) Server support was vulnerable to a null-pointer dereference issue. The flaw could occur when releasing a client, which was not initialized due to failed negotiation. A remote user or process could exploit this flaw to crash the qemu-nbd server (denial of service). (CVE-2017-9524)

Bug Fix(es):

• Previously, when the data plane was in use, changing the target image of a virtual SCSI CD device caused the guest to terminate unexpectedly with a core dump. With this update, the virtio-scsi bus rejects SCSI CDs when the data plane is active, which prevents the crash from occurring. Note that this is a temporary solution, and a full fix to make the data plane and SCSI CD compatible will be provided in the future. (BZ#1461837)

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 Virtualization 4 for RHEL 7 x86_64
• Red Hat Virtualization 3 for RHEL 7 x86_64
• Red Hat Virtualization for IBM Power LE 4 for RHEL 7 ppc64le
• Red Hat Virtualization for IBM Power LE 3 ppc64le

Fixes

• BZ - 1460170 - CVE-2017-9524 Qemu: nbd: segmentation fault due to client non-negotiation
• BZ - 1461837 - Core dump when use "data-plane" and execute change cd

CVEs

• CVE-2017-9524

References

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