Potential dangling pointer in od_backend_connect_to

[arpit-saxena]

In the code below in od_backend_connect_to, we free io pointer and return.

odyssey/sources/backend.c

Lines 311 to 318 in 8bd0ada

	rc = od_io_prepare(&server->io, io, instance->config.readahead);
	if (rc == -1) {
	od_error(&instance->logger, context, NULL, server,
	"failed to set server io");
	machine_close(io);
	machine_io_free(io);
	return -1;
	}

This causes server->io.io to be a dangling pointer, pointing to freed up memory. This can cause issues when we try to access this pointer when doing cleanup after this error. I believe we should set this to NULL after freeing it atleast.