[$] The problem with the asynchronous bsg interface

The kernel supports two different "SCSI generic" pseudo-devices, each ofwhich allows user space to send arbitrary commands to a SCSI-attacheddevice. Both SCSI-generic implementations have proved to have securityissues in the past as a result of the way their API was designed. In thecase of one of those drivers, these problems seem almost certain to lead to theremoval of a significant chunk of functionality in the 4.19 developmentcycle.