A use after free in the SEV firmware could allow a malicous hypervisor to activate a migrated guest with the SINGLE_SOCKET policy on a different socket than the migration agent potentially resulting in loss of integrity.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.