Describe CVE-2021-47061.
What is 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..