Re: [PATCH] char: tmp: fix potential null pointer dereference

[Gustavo A. R. Silva]

Hi Jarkko,

Please, see my comments below

Quoting Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>:

> On Tue, May 30, 2017 at 04:51:23PM -0500, Gustavo A. R. Silva wrote:
> > NULL check at line 147: if (chip) {, implies chip might be NULL.
> > Function dev_get_drvdata() dereference pointer chip.
> > Move pointer priv assignment inside the IF block that checks
> > pointer chip.
> >
> > Addresses-Coverity-ID: 1397646
> > Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
>
> It cannot be.

I got it.

> /Jarkko
>
> > ---
> >  drivers/char/tpm/tpm_atmel.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
> > index 0d322ab..0826efd 100644
> > --- a/drivers/char/tpm/tpm_atmel.c
> > +++ b/drivers/char/tpm/tpm_atmel.c
> > @@ -142,9 +142,10 @@ static struct platform_device *pdev;
> >  static void atml_plat_remove(void)
> >  {
> >  	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
> > -	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
> > +	struct tpm_atmel_priv *priv;
> >
> >  	if (chip) {

So, this NULL check could be removed?

> > +		priv = dev_get_drvdata(&chip->dev);
> >  		tpm_chip_unregister(chip);
> >  		if (priv->have_region)
> >  			atmel_release_region(priv->base, priv->region_size);
> > --
> > 2.5.0

Thank you
--
Gustavo A. R. Silva