2022-06-24 03:11:21

by Hangyu Hua

Subject: [PATCH RESEND] drm: i915: fix a possible refcount leak in intel_dp_add_mst_connector()

If drm_connector_init fails, intel_connector_free will be called to take
care of proper free. So it is necessary to drop the refcount of port
before intel_connector_free.

Fixes: 091a4f91942a ("drm/i915: Handle drm-layer errors in intel_dp_add_mst_connector")
Signed-off-by: Hangyu Hua <[email protected]>
Reviewed-by: José Roberto de Souza <[email protected]>
---
drivers/gpu/drm/i915/display/intel_dp_mst.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 061b277e5ce7..14d2a64193b2 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -839,6 +839,7 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
ret = drm_connector_init(dev, connector, &intel_dp_mst_connector_funcs,
DRM_MODE_CONNECTOR_DisplayPort);
if (ret) {
+ drm_dp_mst_put_port_malloc(port);
intel_connector_free(intel_connector);
return NULL;
}
--
2.25.1

2022-06-28 23:12:46

by Lyude Paul

Subject: Re: [PATCH RESEND] drm: i915: fix a possible refcount leak in intel_dp_add_mst_connector()

Ah-nevermind! Seems like someone already pushed this for you :)

On Tue, 2022-06-28 at 18:55 -0400, Lyude Paul wrote:
> Nice catch!
>
> Reviewed-by: Lyude Paul <[email protected]>
>
> Will push to drm-intel-next
>
> On Fri, 2022-06-24 at 10:28 +0800, Hangyu Hua wrote:
> > If drm_connector_init fails, intel_connector_free will be called to take
> > care of proper free. So it is necessary to drop the refcount of port
> > before intel_connector_free.
> >
> > Fixes: 091a4f91942a ("drm/i915: Handle drm-layer errors in
> > intel_dp_add_mst_connector")
> > Signed-off-by: Hangyu Hua <[email protected]>
> > Reviewed-by: José Roberto de Souza <[email protected]>
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp_mst.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > index 061b277e5ce7..14d2a64193b2 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > @@ -839,6 +839,7 @@ static struct drm_connector
> > *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
> >         ret = drm_connector_init(dev, connector,
> > &intel_dp_mst_connector_funcs,
> >                                  DRM_MODE_CONNECTOR_DisplayPort);
> >         if (ret) {
> > +               drm_dp_mst_put_port_malloc(port);
> >                 intel_connector_free(intel_connector);
> >                 return NULL;
> >         }
>

--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat

2022-06-28 23:14:12

by Lyude Paul

Subject: Re: [PATCH RESEND] drm: i915: fix a possible refcount leak in intel_dp_add_mst_connector()

Nice catch!

Reviewed-by: Lyude Paul <[email protected]>

Will push to drm-intel-next

On Fri, 2022-06-24 at 10:28 +0800, Hangyu Hua wrote:
> If drm_connector_init fails, intel_connector_free will be called to take
> care of proper free. So it is necessary to drop the refcount of port
> before intel_connector_free.
>
> Fixes: 091a4f91942a ("drm/i915: Handle drm-layer errors in
> intel_dp_add_mst_connector")
> Signed-off-by: Hangyu Hua <[email protected]>
> Reviewed-by: José Roberto de Souza <[email protected]>
> ---
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 061b277e5ce7..14d2a64193b2 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -839,6 +839,7 @@ static struct drm_connector
> *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
>         ret = drm_connector_init(dev, connector,
> &intel_dp_mst_connector_funcs,
>                                  DRM_MODE_CONNECTOR_DisplayPort);
>         if (ret) {
> +               drm_dp_mst_put_port_malloc(port);
>                 intel_connector_free(intel_connector);
>                 return NULL;
>         }

--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat