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

[KY Srinivasan]

> -----Original Message-----
> From: Long Li
> Sent: Monday, May 15, 2017 3:48 PM
> To: Long Li <longli@xxxxxxxxxxxxx>; James E.J. Bottomley
> <jejb@xxxxxxxxxxxxxxxxxx>; Martin K. Petersen
> <martin.petersen@xxxxxxxxxx>; linux-scsi@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>; Stephen Hemminger
> <sthemmin@xxxxxxxxxxxxx>
> Subject: RE: [PATCH] scsi: zero per-cmd driver data for each MQ I/O
> 
> > -----Original Message-----
> > From: Long Li [mailto:longli@xxxxxxxxxxxxxxxxxxxxxx]
> > Sent: Wednesday, May 10, 2017 2:07 PM
> > To: James E.J. Bottomley <jejb@xxxxxxxxxxxxxxxxxx>; Martin K. Petersen
> > <martin.petersen@xxxxxxxxxx>; linux-scsi@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx
> > Cc: Long Li <longli@xxxxxxxxxxxxx>
> > Subject: [PATCH] scsi: zero per-cmd driver data for each MQ I/O
> >
> > From: Long Li <longli@xxxxxxxxxxxxx>
> >
> > Lower layer driver may not initialize private data before use. Zero them out
> > to prevent use of stale data.
> >
> > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> 
> Can someone help review this patch?
Reviewed-by:  K. Y. Srinivasan <kys@xxxxxxxxxxxxx>

> 
> > ---
> >  drivers/scsi/scsi_lib.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index
> > 19125d7..a821593 100644
> > --- a/drivers/scsi/scsi_lib.c
> > +++ b/drivers/scsi/scsi_lib.c
> > @@ -1850,7 +1850,7 @@ static int scsi_mq_prep_fn(struct request *req)
> >
> >         /* zero out the cmd, except for the embedded scsi_request */
> >         memset((char *)cmd + sizeof(cmd->req), 0,
> > -               sizeof(*cmd) - sizeof(cmd->req));
> > +               sizeof(*cmd) - sizeof(cmd->req) +
> > + shost->hostt->cmd_size);
> >
> >         req->special = cmd;
> >
> > --
> > 2.7.4