| Description: | KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel.
The x86 emulator implementation was missing a check for the Current Privilege Level (CPL) and I/O Privilege Level (IOPL). A user in a guest could leverage these flaws to cause a denial of service (guest crash) or possibly escalate their privileges within that guest. (CVE-2010-0298, CVE-2010-0306)
A flaw was found in the Programmable Interval Timer (PIT) emulation. Access to the internal data structure pit_state, which represents the data state of the emulated PIT, was not properly validated in the pit_ioport_read() function. A privileged guest user could use this flaw to crash the host. (CVE-2010-0309)
A flaw was found in the USB passthrough handling code. A specially-crafted USB packet sent from inside a guest could be used to trigger a buffer overflow in the usb_host_handle_control() function, which runs under the QEMU-KVM context on the host. A user in a guest could leverage this flaw to cause a denial of service (guest hang or crash) or possibly escalate their privileges within the host. (CVE-2010-0297)
This update also fixes the following bugs:
pvclock MSR values were not preserved during remote migration, causing time drift for guests. (BZ#537028)
SMBIOS table 4 data is now generated for Windows guests. (BZ#545874)
if the qemu-kvm "-net user" option was used, unattended Windows XP installations did not receive an IP address after reboot. (BZ#546562)
when being restored from migration, a race condition caused Windows Server 2008 R2 guests to hang during shutdown. (BZ#546563)
the kernel symbol checking on the kvm-kmod build process has a safety check for ABI changes. (BZ#547293)
on hosts without high-res timers, Windows Server 2003 guests experienced significant time drift. (BZ#547625)
in some situations, installing Windows Server 2008 R2 from an ISO image resulted in a blue screen "BAD_POOL_HEADER" stop error. (BZ#548368)
a bug in the grow_refcount_table() error handling caused infinite recursion in some cases. This caused the qemu-kvm process to hang and eventually crash. (BZ#552159)
for Windows Server 2003 R2, Service Pack 2, 32-bit guests, an "unhandled vm exit" error could occur during reboot on some systems. (BZ#552518)
for Windows guests, QEMU could attempt to stop a stopped audio device, resulting in a "snd_playback_stop: ASSERT playback_channel->base.active failed" error. (BZ#552519)
the Hypercall driver did not reset the device on power-down. (BZ#552528)
mechanisms have been added to make older savevm versions to be emitted in some cases. (BZ#552529)
an error in the Makefile prevented users from using the source RPM to install KVM. (BZ#552530)
guests became unresponsive and could use up to 100% CPU when running certain benchmark tests with more than 7 guests running simultaneously. (BZ#553249)
QEMU could terminate randomly with virtio-net and SMP enabled. (BZ#561022)
All KVM users should upgrade to these updated packages, which contain backported patches to resolve these issues. Note: The procedure in the Solution section must be performed before this update will take effect.
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