Re: [PATCH linux-next v2 1/3] platform/x86/intel/tpmi: Fix double free in tpmi_create_device()

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

Hi Hans,

On Thu, 2023-03-16 at 15:25 +0100, Hans de Goede wrote:
> Hi,
> 
> On 3/9/23 05:01, Dongliang Mu wrote:
> > The previous commit 6a192c0cbf38 ("platform/x86/intel/tpmi: Fix
> > double free reported by Smatch") incorrectly handle the
> > deallocation of
> > res variable. As shown in the comment, intel_vsec_add_aux handles
> > all
> > the deallocation of res and feature_vsec_dev. Therefore, kfree(res)
> > can
> > still cause double free if intel_vsec_add_aux returns error.
> > 
> > Fix this by adjusting the error handling part in
> > tpmi_create_device,
> > following the function intel_vsec_add_dev.
> > 
> > Fixes: 6a192c0cbf38 ("platform/x86/intel/tpmi: Fix double free
> > reported by Smatch")
> > Signed-off-by: Dongliang Mu <dzm91@hust.edu.cn>

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> 
> IIRC then after this v2 was posted I still saw some comments on the
> original v1 which was not posted on the list. Without the v1 comments
> being on the list and this archived, I have lost track of what the
> status of these patches is.
> 
> Srinivas, can you let me know if I should merge these, or if more
> changes are necessary ?
> 
> From the off-list discussion of v1 I got the impression more changes
> are necessary, but I'm not sure.

I was looking for changes submitted by the following patch
"
[PATCH linux-next v2 3/3] drivers/platform/x86/intel: fix a memory leak
in intel_vsec_add_aux
"

Since I was not copied on this, I was unaware. So I was requesting this
change.

Thanks,
Srinivas

> 
> Regards,
> 
> Hans
> 
> 
> 
> 
> > ---
> >  drivers/platform/x86/intel/tpmi.c | 17 ++++-------------
> >  1 file changed, 4 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/platform/x86/intel/tpmi.c
> > b/drivers/platform/x86/intel/tpmi.c
> > index c999732b0f1e..882fe5e4763f 100644
> > --- a/drivers/platform/x86/intel/tpmi.c
> > +++ b/drivers/platform/x86/intel/tpmi.c
> > @@ -215,8 +215,8 @@ static int tpmi_create_device(struct
> > intel_tpmi_info *tpmi_info,
> >  
> >         feature_vsec_dev = kzalloc(sizeof(*feature_vsec_dev),
> > GFP_KERNEL);
> >         if (!feature_vsec_dev) {
> > -               ret = -ENOMEM;
> > -               goto free_res;
> > +               kfree(res);
> > +               return -ENOMEM;
> >         }
> >  
> >         snprintf(feature_id_name, sizeof(feature_id_name), "tpmi-
> > %s", name);
> > @@ -242,17 +242,8 @@ static int tpmi_create_device(struct
> > intel_tpmi_info *tpmi_info,
> >          * feature_vsec_dev memory is also freed as part of device
> >          * delete.
> >          */
> > -       ret = intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev-
> > >auxdev.dev,
> > -                                feature_vsec_dev,
> > feature_id_name);
> > -       if (ret)
> > -               goto free_res;
> > -
> > -       return 0;
> > -
> > -free_res:
> > -       kfree(res);
> > -
> > -       return ret;
> > +       return intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev-
> > >auxdev.dev,
> > +                                 feature_vsec_dev,
> > feature_id_name);
> >  }
> >  
> >  static int tpmi_create_devices(struct intel_tpmi_info *tpmi_info)
>