Re: [PATCH] staging: media: lirc: lirc_zilog: Fix for possible null pointer dereference

[Dan Carpenter <dan.carpenter@oracle.com>]

On Thu, Jan 29, 2015 at 05:12:40PM -0500, Valdis.Kletnieks@vt.edu wrote:
> On Thu, 29 Jan 2015 19:48:08 +0100, Rickard Strandqvist said:
> > Fix a possible null pointer dereference, there is
> > otherwise a risk of a possible null pointer dereference.
> >
> > This was found using a static code analysis program called cppcheck
> >
> > Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
> > ---
> >  drivers/staging/media/lirc/lirc_zilog.c |    4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> >  	/* find our IR struct */
> >  	struct IR *ir = filep->private_data;
> >
> > -	if (ir == NULL) {
> > -		dev_err(ir->l.dev, "close: no private_data attached to the file!\n");
> 
> Yes, the dev_err() call is an obvious thinko.
> 
> However, I'm not sure whether removing it entirely is right either.  If
> there *should* be a struct IR * passed there, maybe some other printk()
> should be issued, or even a WARN_ON(!ir), or something?

We set filep->private_data to non-NULL in open() so I don't think it can
be NULL here.

regards,
dan carpenter