CVE-2021-47061

In the Linux kernel, the following vulnerability has been resolved: KVM:
Destroy I/O bus devices on unregister failure after sync’ing SRCU If
allocating a new instance of an I/O bus fails when unregistering a device,
wait to destroy the device until after all readers are guaranteed to see
the new null bus. Destroying devices before the bus is nullified could lead
to use-after-free since readers expect the devices on their reference of
the bus to remain valid.