[Intel-gfx] [PATCH 1/2] drm/i915/gvt: Avoid use-after-free iterating the gtt list

[Yuan, Hang]

Sorry I missed it. Thanks for the correction!

Regards,
Henry

> -----Original Message-----
> From: Zhenyu Wang [mailto:zhenyuw at linux.intel.com]
> Sent: Wednesday, November 21, 2018 10:29 AM
> To: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: intel-gfx at lists.freedesktop.org; Zhenyu Wang
> <zhenyuw at linux.intel.com>; Yuan, Hang <hang.yuan at intel.com>
> Subject: Re: [PATCH 1/2] drm/i915/gvt: Avoid use-after-free iterating the gtt
> list
> 
> On 2018.11.20 20:24:38 +0000, Chris Wilson wrote:
> > Found by smatch:
> >
> > drivers/gpu/drm/i915/gvt/gtt.c:2452 intel_vgpu_destroy_ggtt_mm() error:
> dereferencing freed memory 'pos'
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/gvt/gtt.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gvt/gtt.c
> > b/drivers/gpu/drm/i915/gvt/gtt.c index 58e166effa45..c7103dd2d8d5
> > 100644
> > --- a/drivers/gpu/drm/i915/gvt/gtt.c
> > +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> > @@ -2447,10 +2447,11 @@ static void
> > intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu)
> >
> >  static void intel_vgpu_destroy_ggtt_mm(struct intel_vgpu *vgpu)  {
> > -	struct intel_gvt_partial_pte *pos;
> > +	struct intel_gvt_partial_pte *pos, *next;
> >
> > -	list_for_each_entry(pos,
> > -			&vgpu->gtt.ggtt_mm->ggtt_mm.partial_pte_list, list) {
> > +	list_for_each_entry_safe(pos, next,
> > +				 &vgpu->gtt.ggtt_mm-
> >ggtt_mm.partial_pte_list,
> > +				 list) {
> >  		gvt_dbg_mm("partial PTE update on hold 0x%lx : 0x%llx\n",
> >  			pos->offset, pos->data);
> >  		kfree(pos);
> 
> Reviewed-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> 
> Thanks! I should really run check against each one when apply..
> 
> --
> Open Source Technology Center, Intel ltd.
> 
> $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827