CVE-2024-36912

In the Linux kernel, the following vulnerability has been resolved:

Drivers: hv: vmbus: Track decrypted status in vmbus_gpadl

In CoCo VMs it is possible for the untrusted host to cause

set_memory_encrypted() or set_memory_decrypted() to fail such that an

error is returned and the resulting memory is shared. Callers need to

take care to handle these errors to avoid returning decrypted (shared)

memory to the page allocator, which could lead to functional or security

issues.

In order to make sure callers of vmbus_establish_gpadl() and

vmbus_teardown_gpadl() don't return decrypted/shared pages to

allocators, add a field in struct vmbus_gpadl to keep track of the

decryption status of the buffers. This will allow the callers to

know if they should free or leak the pages.