On Mon, May 09, 2022 at 03:50:33PM +0100, John Garry wrote: > If you check scsi_device_dev_release(), we try to do a 'get' - if it fails, > then we nullify hostt->module. I think that is important as then we call > execute_in_process_context(), whose worker does the 'put'. However, the > 'put' will get upset if the refcnt was 0, which it would be if the earlier > 'get' fails - hence the nullify is to avoid that possibility. So whatever > you do needs to handle that. Details are in f2b85040 Yikes, that code is completely and utterly buggy and does not account for all the cases why try_module_get can fail. I think we always have a reference here and could use __module_get, but what we have is certainly unsafe and a good reason why the host template should be constifyed.
