Re: [PATCH 1/2] scsi: Fix get_user() in call sg_scsi_ioctl()

[kirill@xxxxxxxxxxxxx]

On Wed, Nov 16, 2022 at 10:40:09PM +0000, David Laight wrote:
> From: Kirill A. Shutemov
> > Sent: 16 November 2022 00:44
> > 
> > get_user() expects the pointer to be pointer-to-simple-variable type,
> > but sic->data is array of 'unsigned char'. It violates get_user()
> > contracts.
> > 
> > Cast it explicitly to 'unsigned char __user *'. It matches current
> > behaviour.
> > 
> > This is preparation for fixing sparse warnings caused by Linear Address
> > Masking patchset.
> > 
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> > Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> > Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> > ---
> >  drivers/scsi/scsi_ioctl.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
> > index 2d20da55fb64..72b3ab5137b8 100644
> > --- a/drivers/scsi/scsi_ioctl.c
> > +++ b/drivers/scsi/scsi_ioctl.c
> > @@ -519,7 +519,7 @@ static int sg_scsi_ioctl(struct request_queue *q, fmode_t mode,
> >  		return -EFAULT;
> >  	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
> >  		return -EINVAL;
> > -	if (get_user(opcode, sic->data))
> > +	if (get_user(opcode, (unsigned char __user *)sic->data))
> 
> Using &sic->data[0] should work and is much nicer than the cast.

Okay. Fair enough. Adjusted patch is below.