Re: [PATCH] staging: i4l: icn: use memdup_user

From: Greg Kroah-Hartman
Date: Tue Aug 23 2016 - 09:07:54 EST


On Tue, Aug 23, 2016 at 04:28:12PM +0530, Sudip Mukherjee wrote:
> On Tue, Aug 23, 2016 at 06:50:30AM -0400, Greg Kroah-Hartman wrote:
> > On Tue, Aug 23, 2016 at 03:57:34PM +0530, Sudip Mukherjee wrote:
> > > Its better to use memdup_user which does the same thing which this
> > > code has implemented.
> > >
> > > Suggested-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> > > Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/staging/i4l/icn/icn.c | 16 +++++-----------
> > > 1 file changed, 5 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/staging/i4l/icn/icn.c b/drivers/staging/i4l/icn/icn.c
> > > index b2f4055..5312675 100644
> > > --- a/drivers/staging/i4l/icn/icn.c
> > > +++ b/drivers/staging/i4l/icn/icn.c
> > > @@ -804,21 +804,16 @@ static int
> > > icn_loadboot(u_char __user *buffer, icn_card *card)
> > > {
> > > int ret;
> > > - u_char *codebuf;
> > > + void *codebuf;
> >
> > why did you change the type here?
>
> type was changed as codebuf is only used with memdup_user() and
> memcpy_toio() and both of them takes void. I should have mentioned
> that in the commit message. Sending v2 with this change and after
> removing the warning.

No, please leave the type alone, you are changing it for no good reason
(and in fact, it might be a bad change if anything else were to use that
pointer...)

greg k-h