On 2021/03/09 1:27, Shuah Khan wrote: > Yes. We might need synchronization between events, threads, and shutdown > in usbip_host side and in connection polling and threads in vhci. > > I am also looking at the shutdown sequences closely as well since the > local state is referenced without usbip_device lock in these paths. > > I am approaching these problems as peeling the onion an expression so > we can limit the changes and take a spot fix approach. We have the > goal to address these crashes and not introduce regressions. I think my [PATCH v4 01/12]-[PATCH v4 06/12] simplify your further changes without introducing regressions. While ud->lock is held when checking ud->status, current attach/detach code is racy about read/update of ud->status . I think we can close race in attach/detach code via a simple usbip_event_mutex serialization.