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.
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| @@ -832,6 +832,7 @@ struct vmbus_gpadl { · 831 unmodified lines | |||
| 832 | u32 gpadl_handle; | 832 | u32 gpadl_handle; |
| 833 | u32 size; | 833 | u32 size; |
| 834 | void *buffer; | 834 | void *buffer; |
| 835 | bool decrypted; | ||
| 835 | }; | 836 | }; |
| 836 | 837 | ||
| 837 | struct vmbus_channel { | 838 | struct vmbus_channel { |