Re: [PATCH 4/6] usbip: fix stub_dev usbip_sockfd_store() races leading to gpf
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: 2021-03-09 23:41:10
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On 2021/03/10 4:50, Shuah Khan wrote:
On 3/9/21 4:04 AM, Tetsuo Handa wrote:quoted
On 2021/03/09 1:27, Shuah Khan wrote:quoted
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".