Re: [PATCH] thermal/int340x_thermal: handle data_vault when the value is ZERO_SIZE_PTR

[joeyli]

On Tue, Aug 23, 2022 at 07:53:18PM +0200, Rafael J. Wysocki wrote:
> On Mon, Aug 8, 2022 at 3:22 PM Lee, Chun-Yi <joeyli.kernel@xxxxxxxxx> wrote:
> >
> > In some case, the GDDV returns a package with a buffer which has
> > zero length. It causes that kmemdup() returns ZERO_SIZE_PTR (0x10).
> >
> > Then the data_vault_read() got NULL point dereference problem when
> > accessing the 0x10 value in data_vault.
> >
> > [   71.024560] BUG: kernel NULL pointer dereference, address:
> > 0000000000000010
> >
> > This patch uses ZERO_OR_NULL_PTR() for checking ZERO_SIZE_PTR or
> > NULL value in data_vault.
> >
> > Signed-off-by: "Lee, Chun-Yi" <jlee@xxxxxxxx>
> 
> Applied as 6.0-rc material, thanks!

Thanks for Rafael's help!

Joey Lee

> 
> > ---
> >  drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 9 +++++----
> >  1 file changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> > index 80d4e0676083..365489bf4b8c 100644
> > --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> > +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> > @@ -527,7 +527,7 @@ static void int3400_setup_gddv(struct int3400_thermal_priv *priv)
> >         priv->data_vault = kmemdup(obj->package.elements[0].buffer.pointer,
> >                                    obj->package.elements[0].buffer.length,
> >                                    GFP_KERNEL);
> > -       if (!priv->data_vault)
> > +       if (ZERO_OR_NULL_PTR(priv->data_vault))
> >                 goto out_free;
> >
> >         bin_attr_data_vault.private = priv->data_vault;
> > @@ -597,7 +597,7 @@ static int int3400_thermal_probe(struct platform_device *pdev)
> >                         goto free_imok;
> >         }
> >
> > -       if (priv->data_vault) {
> > +       if (!ZERO_OR_NULL_PTR(priv->data_vault)) {
> >                 result = sysfs_create_group(&pdev->dev.kobj,
> >                                             &data_attribute_group);
> >                 if (result)
> > @@ -615,7 +615,8 @@ static int int3400_thermal_probe(struct platform_device *pdev)
> >  free_sysfs:
> >         cleanup_odvp(priv);
> >         if (priv->data_vault) {
> > -               sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
> > +               if (!ZERO_OR_NULL_PTR(priv->data_vault))
> > +                       sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
> >                 kfree(priv->data_vault);
> >         }
> >  free_uuid:
> > @@ -647,7 +648,7 @@ static int int3400_thermal_remove(struct platform_device *pdev)
> >         if (!priv->rel_misc_dev_res)
> >                 acpi_thermal_rel_misc_device_remove(priv->adev->handle);
> >
> > -       if (priv->data_vault)
> > +       if (!ZERO_OR_NULL_PTR(priv->data_vault))
> >                 sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
> >         sysfs_remove_group(&pdev->dev.kobj, &uuid_attribute_group);
> >         sysfs_remove_group(&pdev->dev.kobj, &imok_attribute_group);
> > --
> > 2.26.2
> >