In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Reset IRTE to host control if new route isnt postable
Restore an IRTE back to host control (remapped or posted MSI mode) if the new GSI route prevents posting the IRQ directly to a vCPU, regardless of the GSI routing type. Updating the IRTE if and only if the new GSI is an MSI results in KVM leaving an IRTE posting to a vCPU.
The dangling IRTE can result in interrupts being incorrectly delivered to the guest, and in the worst case scenario can result in use-after-free, e.g. if the VM is torn down, but the underlying host IRQ isnt freed.