In the Linux kernel, the following vulnerability has been resolved: ublk: wait on ublk_dev_ready() instead of ub->completion ub->completion is only re-armed by a successful START_USER_RECOVERY. If the ublk server sends END_USER_RECOVERY without one - e.g. its START failed with -EBUSY and the error was ignored - the wait is satisfied by the stale completion of the previous recovery cycle, and the device is marked LIVE and the requeue list kicked while the FETCH stream is still running and ubq->