On 2021/03/10 4:50, Shuah Khan wrote: > On 3/9/21 4:04 AM, Tetsuo Handa wrote: >> 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. >> > > Do you mean patches 1,2,3,3,4,5,6? Yes, my 1,2,3,4,5,6. Since you think that usbip_prepare_threads() does not worth introducing, I'm fine with replacing my 7,8,9,10,11,12 with your "[PATCH 0/6] usbip fixes to crashes found by syzbot".
