efi_loader: AllocateAddress requires page address

AllocatePages() can be called with Type=AllocateAddress. Such a call can
only succeed if *Memory points to the address of an unallocated page range.

A call with *Memory being an address that is not page aligned must not
succeed. The UEFI specification requires returning EFI_OUT_OF_RESOURCES
if the requested pages cannot be allocated.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index e048a54..a17b426 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -483,6 +483,8 @@
 			return EFI_OUT_OF_RESOURCES;
 		break;
 	case EFI_ALLOCATE_ADDRESS:
+		if (*memory & EFI_PAGE_MASK)
+			return EFI_NOT_FOUND;
 		/* Exact address, reserve it. The addr is already in *memory. */
 		ret = efi_check_allocated(*memory, false);
 		if (ret != EFI_SUCCESS)