[PATCH v5 1/3] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()

[PATCH v5 1/3] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()

[Biju Das]

The host_node pointer was assigned and freed in adv7533_parse_dt(), and
later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue
by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put()
in error path of probe() and also in the remove().

Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
Changes in v5:
 - Updated commit description.
 - restored host_node in struct adv7511.
 - Dropped of_node_put() in adv7533_parse_dt() and calling of_node_put()
   in error path of probe() and also in the remove().
Changes in v4:
 - Updated commit description.
 - Dropped host_node from struct adv7511 and instead used a local pointer
   in probe(). Also freeing of host_node pointer after use is done in
   probe().
Changes in v3:
 - Replace __free construct with readable of_node_put().
Changes in v2:
 - Added the tag "Cc: stable@vger.kernel.org" in the sign-off area.
 - Dropped Archit Taneja invalid Mail address
---
 drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 +++++
 drivers/gpu/drm/bridge/adv7511/adv7533.c     | 2 --
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index eb5919b38263..6cfdda04f52f 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1363,6 +1363,8 @@ static int adv7511_probe(struct i2c_client *i2c)
 	i2c_unregister_device(adv7511->i2c_edid);
 uninit_regulators:
 	adv7511_uninit_regulators(adv7511);
+	if (adv7511->host_node)
+		of_node_put(adv7511->host_node);
 
 	return ret;
 }
@@ -1371,6 +1373,9 @@ static void adv7511_remove(struct i2c_client *i2c)
 {
 	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
 
+	if (adv7511->host_node)
+		of_node_put(adv7511->host_node);
+
 	adv7511_uninit_regulators(adv7511);
 
 	drm_bridge_remove(&adv7511->bridge);
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
index 4481489aaf5e..5f195e91b3e6 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
@@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
 	if (!adv->host_node)
 		return -ENODEV;
 
-	of_node_put(adv->host_node);
-
 	adv->use_timing_gen = !of_property_read_bool(np,
 						"adi,disable-timing-generator");
 
-- 
2.43.0

[PATCH v5 2/3] dt-bindings: display: adi,adv7533: Drop single lane support

[Biju Das]

As per [1] and [2], ADV7535/7533 supports only 2-, 3-, or 4-lane. Drop
unsupported 1-lane from bindings.

[1] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7535.pdf
[2] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7533.pdf

Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
Cc: stable@vger.kernel.org
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v4->v5:
 * No change.
v3->v4:
 * Added link to ADV7533 data sheet.
 * Collected tags.
v3:
 * New patch.
---
 .../devicetree/bindings/display/bridge/adi,adv7533.yaml         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/adi,adv7533.yaml b/Documentation/devicetree/bindings/display/bridge/adi,adv7533.yaml
index df20a3c9c744..ec89115c74e4 100644
--- a/Documentation/devicetree/bindings/display/bridge/adi,adv7533.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/adi,adv7533.yaml
@@ -90,7 +90,7 @@ properties:
   adi,dsi-lanes:
     description: Number of DSI data lanes connected to the DSI host.
     $ref: /schemas/types.yaml#/definitions/uint32
-    enum: [ 1, 2, 3, 4 ]
+    enum: [ 2, 3, 4 ]
 
   "#sound-dai-cells":
     const: 0
-- 
2.43.0

[PATCH v5 3/3] drm: adv7511: Drop dsi single lane support

[Biju Das]

As per [1] and [2], ADV7535/7533 supports only 2-, 3-, or 4-lane. Drop
unsupported 1-lane.

[1] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7535.pdf
[2] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7533.pdf

Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
Reported-by: Hien Huynh <hien.huynh.px@renesas.com>
Cc: stable@vger.kernel.org
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
Changes in v5:
 - No change.
Changes in v4:
 - Added link to ADV7533 data sheet.
 - Collected tags
Changes in v3:
 - Updated commit header and description
 - Updated fixes tag
 - Dropped single lane support
Changes in v2:
 - Added the tag "Cc: stable@vger.kernel.org" in the sign-off area.
 - Dropped Archit Taneja invalid Mail address
---
 drivers/gpu/drm/bridge/adv7511/adv7533.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
index 5f195e91b3e6..122ad91e8a32 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
@@ -172,7 +172,7 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
 
 	of_property_read_u32(np, "adi,dsi-lanes", &num_lanes);
 
-	if (num_lanes < 1 || num_lanes > 4)
+	if (num_lanes < 2 || num_lanes > 4)
 		return -EINVAL;
 
 	adv->num_dsi_lanes = num_lanes;
-- 
2.43.0

Re: [PATCH v5 3/3] drm: adv7511: Drop dsi single lane support

[Adam Ford]

On Tue, Nov 19, 2024 at 7:50 AM Biju Das <biju.das.jz@bp.renesas.com> wrote:
>
> As per [1] and [2], ADV7535/7533 supports only 2-, 3-, or 4-lane. Drop
> unsupported 1-lane.
>
> [1] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7535.pdf
> [2] https://www.analog.com/media/en/technical-documentation/data-sheets/ADV7533.pdf

Thanks for doing that. I never noticed it only supported 2,3 or 4
lanes, but this patch makes sense to me.
>
> Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
> Reported-by: Hien Huynh <hien.huynh.px@renesas.com>
> Cc: stable@vger.kernel.org

Reviewed-by: Adam Ford <aford173@gmail.com>

> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> Changes in v5:
>  - No change.
> Changes in v4:
>  - Added link to ADV7533 data sheet.
>  - Collected tags
> Changes in v3:
>  - Updated commit header and description
>  - Updated fixes tag
>  - Dropped single lane support
> Changes in v2:
>  - Added the tag "Cc: stable@vger.kernel.org" in the sign-off area.
>  - Dropped Archit Taneja invalid Mail address
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7533.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> index 5f195e91b3e6..122ad91e8a32 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> @@ -172,7 +172,7 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
>
>         of_property_read_u32(np, "adi,dsi-lanes", &num_lanes);
>
> -       if (num_lanes < 1 || num_lanes > 4)
> +       if (num_lanes < 2 || num_lanes > 4)
>                 return -EINVAL;
>
>         adv->num_dsi_lanes = num_lanes;
> --
> 2.43.0
>
>

Re: [PATCH v5 1/3] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()

[Laurent Pinchart]

Hi Biju,

Thank you for the patch.

On Tue, Nov 19, 2024 at 01:10:03PM +0000, Biju Das wrote:
> The host_node pointer was assigned and freed in adv7533_parse_dt(), and
> later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue
> by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put()
> in error path of probe() and also in the remove().
> 
> Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
> Cc: stable@vger.kernel.org
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> Changes in v5:
>  - Updated commit description.
>  - restored host_node in struct adv7511.
>  - Dropped of_node_put() in adv7533_parse_dt() and calling of_node_put()
>    in error path of probe() and also in the remove().
> Changes in v4:
>  - Updated commit description.
>  - Dropped host_node from struct adv7511 and instead used a local pointer
>    in probe(). Also freeing of host_node pointer after use is done in
>    probe().
> Changes in v3:
>  - Replace __free construct with readable of_node_put().
> Changes in v2:
>  - Added the tag "Cc: stable@vger.kernel.org" in the sign-off area.
>  - Dropped Archit Taneja invalid Mail address
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 +++++
>  drivers/gpu/drm/bridge/adv7511/adv7533.c     | 2 --
>  2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index eb5919b38263..6cfdda04f52f 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -1363,6 +1363,8 @@ static int adv7511_probe(struct i2c_client *i2c)
>  	i2c_unregister_device(adv7511->i2c_edid);
>  uninit_regulators:
>  	adv7511_uninit_regulators(adv7511);
> +	if (adv7511->host_node)
> +		of_node_put(adv7511->host_node);

This won't be called when adv7511_init_regulators() fails as the driver
returns directly then, leaking the reference. You need a new error label
and a goto for that error path.

In the future, when touching error handling, please try to check
existing error paths and verify they're still right.

>  
>  	return ret;
>  }
> @@ -1371,6 +1373,9 @@ static void adv7511_remove(struct i2c_client *i2c)
>  {
>  	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
>  
> +	if (adv7511->host_node)
> +		of_node_put(adv7511->host_node);
> +
>  	adv7511_uninit_regulators(adv7511);
>  
>  	drm_bridge_remove(&adv7511->bridge);
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> index 4481489aaf5e..5f195e91b3e6 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
>  	if (!adv->host_node)
>  		return -ENODEV;
>  
> -	of_node_put(adv->host_node);
> -
>  	adv->use_timing_gen = !of_property_read_bool(np,
>  						"adi,disable-timing-generator");
>  

-- 
Regards,

Laurent Pinchart

RE: [PATCH v5 1/3] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()

[Biju Das]

Hi Laurent,

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Sent: 19 November 2024 16:28
> Subject: Re: [PATCH v5 1/3] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()
> 
> Hi Biju,
> 
> Thank you for the patch.
> 
> On Tue, Nov 19, 2024 at 01:10:03PM +0000, Biju Das wrote:
> > The host_node pointer was assigned and freed in adv7533_parse_dt(),
> > and later, adv7533_attach_dsi() uses the same. Fix this use-after-free
> > issue by dropping of_node_put() in adv7533_parse_dt() and calling
> > of_node_put() in error path of probe() and also in the remove().
> >
> > Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > ---
> > Changes in v5:
> >  - Updated commit description.
> >  - restored host_node in struct adv7511.
> >  - Dropped of_node_put() in adv7533_parse_dt() and calling of_node_put()
> >    in error path of probe() and also in the remove().
> > Changes in v4:
> >  - Updated commit description.
> >  - Dropped host_node from struct adv7511 and instead used a local pointer
> >    in probe(). Also freeing of host_node pointer after use is done in
> >    probe().
> > Changes in v3:
> >  - Replace __free construct with readable of_node_put().
> > Changes in v2:
> >  - Added the tag "Cc: stable@vger.kernel.org" in the sign-off area.
> >  - Dropped Archit Taneja invalid Mail address
> > ---
> >  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 5 +++++
> >  drivers/gpu/drm/bridge/adv7511/adv7533.c     | 2 --
> >  2 files changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > index eb5919b38263..6cfdda04f52f 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > @@ -1363,6 +1363,8 @@ static int adv7511_probe(struct i2c_client *i2c)
> >  	i2c_unregister_device(adv7511->i2c_edid);
> >  uninit_regulators:
> >  	adv7511_uninit_regulators(adv7511);
> > +	if (adv7511->host_node)
> > +		of_node_put(adv7511->host_node);
> 
> This won't be called when adv7511_init_regulators() fails as the driver returns directly then, leaking
> the reference. You need a new error label and a goto for that error path.

Oops missed again.
> 
> In the future, when touching error handling, please try to check existing error paths and verify
> they're still right.

Yes, will take care next time.

Cheers,
Biju

> 
> >
> >  	return ret;
> >  }
> > @@ -1371,6 +1373,9 @@ static void adv7511_remove(struct i2c_client
> > *i2c)  {
> >  	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
> >
> > +	if (adv7511->host_node)
> > +		of_node_put(adv7511->host_node);
> > +
> >  	adv7511_uninit_regulators(adv7511);
> >
> >  	drm_bridge_remove(&adv7511->bridge);
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > index 4481489aaf5e..5f195e91b3e6 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c
> > @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
> >  	if (!adv->host_node)
> >  		return -ENODEV;
> >
> > -	of_node_put(adv->host_node);
> > -
> >  	adv->use_timing_gen = !of_property_read_bool(np,
> >  						"adi,disable-timing-generator");
> >
> 
> --
> Regards,
> 
> Laurent Pinchart