Re: [PATCH] staging: wimax: fix sparse incorrect type issue

[karthek]

On Mon, Feb 22, 2021 at 11:10 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> On Sat, Feb 20, 2021 at 05:04:00PM +0530, karthik alapati wrote:
> > fix sparse warning by casting to explicit user address-space
> > pointer type
> >
> > Signed-off-by: karthik alapati <mail@xxxxxxxxxxx>
> > ---
> >  drivers/staging/wlan-ng/p80211netdev.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
> > index 6f9666dc0..70570e8a5 100644
> > --- a/drivers/staging/wlan-ng/p80211netdev.c
> > +++ b/drivers/staging/wlan-ng/p80211netdev.c
> > @@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
> >               goto bail;
> >       }
> >
> > -     msgbuf = memdup_user(req->data, req->len);
> > +     msgbuf = memdup_user((void __user *)req->data, req->len);
>
> This doesn't fix anything it just silences the warning.  Linus Torvalds
> worked very hard to create Sparse for the express purpose of printing
> the warning.  People don't realize that warnings are very valuable
> because they show where the bugs are.
>
> Please look at this some more and figure out how to fix the warning.
>
> To be honest, I'm tempted to not accept any patch which doesn't also fix
> the buffer overflows when we pass:
>
>         result = p80211req_dorequest(wlandev, msgbuf);
>
> How do we know that "msgbuf" is large enough?
>
> regards,
> dan carpenter
>

Thanks dan but right after sending this patch i immediately replied to
it stating
to ignore this patch as i found this already applied in staging-testing branch
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git/commit/?h=staging-testing&id=3a8a144d2a754df45127c74e273fa166f690ba43