qemu-kvm (SL7)

Synopsis: Moderate: qemu-kvm security and bug fix update
Advisory ID: SLSA-2014:0704-1
Issue Date: 2014-06-10
CVE Numbers: CVE-2014-2894

An out-of-bounds memory access flaw was found in the way QEMU’s IDE device
driver handled the execution of SMART EXECUTE OFFLINE commands. A
privileged guest user could use this flaw to corrupt QEMU process memory
on the host, which could potentially result in arbitrary code execution on
the host with the privileges of the QEMU process. (CVE-2014-2894)

This update also fixes the following bugs:

* Prior to this update, a bug in the migration code caused the following
error on specific machine types: after a Scientific Linux 6.5 guest was
migrated from a Scientific Linux 6.5 host to a Scientific Linux 7.0 host
and then restarted, the boot failed and the guest automatically restarted.
Thus, the guest entered an endless loop. With this update, the migration
code has been fixed and the Scientific Linux 6.5 guests migrated in the
aforementioned scenario now boot properly.

* Due to a regression bug in the iSCSI driver, the qemu-kvm process
terminated unexpectedly with a segmentation fault when the “write same”
command was executed in guest mode under the iSCSI protocol. This update
fixes the regression and the “write same” command now functions in guest
mode under iSCSI as intended.

* Due to a mismatch in interrupt request (IRQ) routing, migration of a
Scientific Linux 6.5 guest from a Scientific Linux 6.5 host to a
Scientific Linux 7.0 host could produce a call trace. This happened if
memory ballooning and a Universal Host Control Interface (UHCI) device
were used at the same time on certain machine types. With this patch, the
IRQ routing mismatch has been amended and the described migration now
proceeds as expected.

* Previously, an internal error prevented KVM from executing a CPU hot
plug on a Scientific Linux 7 guest running on a Scientific Linux 7 host.
This update addresses the internal error and CPU hot plugging in the
described scenario now functions correctly.

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.


– Scientific Linux Development Team