Red Hat Security Advisory 2015-0869-01 - KVM 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. It was found that KVM's Write to Model Specific Register instruction emulation would write non-canonical values passed in by the guest to certain MSRs in the host's context. A privileged guest user could use this flaw to crash the host. A race condition flaw was found in the way the Linux kernel's KVM subsystem handled PIT emulation. A guest user who has access to the PIT I/O ports could use this flaw to crash the host.
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