Re: [PATCH v2] scsi: zero per-cmd private driver data for each MQ I/O

From: Martin K. Petersen
Date: Thu May 18 2017 - 21:46:31 EST


> In lower layer driver's (LLD) scsi_host_template, the driver may
> optionally ask SCSI to allocate its private driver memory for each
> command, by specifying cmd_size. This memory is allocated at the end
> of scsi_cmnd by SCSI. Later when SCSI queues a command, the LLD can
> use scsi_cmd_priv to get to its private data.
> Some LLD, e.g. hv_storvsc, doesn't clear its private data before
> use. In this case, the LLD may get to stale or uninitialized data in
> its private driver memory. This may result in unexpected driver and
> hardware behavior.
> Fix this problem by also zeroing the private driver memory before
> passing them to LLD.

Applied to 4.12/scsi-fixes. Thank you!

Martin K. Petersen Oracle Linux Engineering