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* [PATCH] drm/bridge: sii902x: Variable status in sii902x_connector_detect() could be uninitialized if regmap_read() fails
@ 2019-09-30  4:45 ` Yizhuo
  0 siblings, 0 replies; 3+ messages in thread
From: Yizhuo @ 2019-09-30  4:45 UTC (permalink / raw)
  Cc: csong, zhiyunq, Yizhuo, Andrzej Hajda, Neil Armstrong,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, dri-devel, linux-kernel

In function sii902x_connector_detect(), variable "status" could be
initialized if regmap_read() fails. However, "status" is used to
decide the return value, which is potentially unsafe.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/gpu/drm/bridge/sii902x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index 38f75ac580df..afce64f51ff2 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -246,7 +246,7 @@ static enum drm_connector_status
 sii902x_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct sii902x *sii902x = connector_to_sii902x(connector);
-	unsigned int status;
+	unsigned int status = 0;
 
 	mutex_lock(&sii902x->mutex);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [PATCH] drm/bridge: sii902x: Variable status in sii902x_connector_detect() could be uninitialized if regmap_read() fails
@ 2019-09-30  4:45 ` Yizhuo
  0 siblings, 0 replies; 3+ messages in thread
From: Yizhuo @ 2019-09-30  4:45 UTC (permalink / raw)
  Cc: csong, zhiyunq, Yizhuo, Andrzej Hajda, Neil Armstrong,
	Laurent Pinchart, Jonas Karlman, Jernej Skrabec, David Airlie,
	Daniel Vetter, dri-devel, linux-kernel

In function sii902x_connector_detect(), variable "status" could be
initialized if regmap_read() fails. However, "status" is used to
decide the return value, which is potentially unsafe.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/gpu/drm/bridge/sii902x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index 38f75ac580df..afce64f51ff2 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -246,7 +246,7 @@ static enum drm_connector_status
 sii902x_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct sii902x *sii902x = connector_to_sii902x(connector);
-	unsigned int status;
+	unsigned int status = 0;
 
 	mutex_lock(&sii902x->mutex);
 
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH] drm/bridge: sii902x: Variable status in sii902x_connector_detect() could be uninitialized if regmap_read() fails
  2019-09-30  4:45 ` Yizhuo
  (?)
@ 2019-10-04  7:02 ` Laurent Pinchart
  -1 siblings, 0 replies; 3+ messages in thread
From: Laurent Pinchart @ 2019-10-04  7:02 UTC (permalink / raw)
  To: Yizhuo
  Cc: csong, zhiyunq, Andrzej Hajda, Neil Armstrong, Jonas Karlman,
	Jernej Skrabec, David Airlie, Daniel Vetter, dri-devel,
	linux-kernel

Hi Yizhuo,

Thank you for the patch.

On Sun, Sep 29, 2019 at 09:45:02PM -0700, Yizhuo wrote:
> In function sii902x_connector_detect(), variable "status" could be
> initialized if regmap_read() fails. However, "status" is used to

I assume you meant "could be uninitialized" ?

> decide the return value, which is potentially unsafe.
> 
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
>  drivers/gpu/drm/bridge/sii902x.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
> index 38f75ac580df..afce64f51ff2 100644
> --- a/drivers/gpu/drm/bridge/sii902x.c
> +++ b/drivers/gpu/drm/bridge/sii902x.c
> @@ -246,7 +246,7 @@ static enum drm_connector_status
>  sii902x_connector_detect(struct drm_connector *connector, bool force)
>  {
>  	struct sii902x *sii902x = connector_to_sii902x(connector);
> -	unsigned int status;
> +	unsigned int status = 0;
>  
>  	mutex_lock(&sii902x->mutex);

I'll add a bit more context:

> 	regmap_read(sii902x->regmap, SII902X_INT_STATUS, &status);
>
> 	mutex_unlock(&sii902x->mutex);
>
> 	return (status & SII902X_PLUGGED_STATUS) ?
> 	       connector_status_connected : connector_status_disconnected;

If regmap read fails, shouldn't we return connector_status_unknown ?

-- 
Regards,

Laurent Pinchart

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-10-04  7:02 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-09-30  4:45 [PATCH] drm/bridge: sii902x: Variable status in sii902x_connector_detect() could be uninitialized if regmap_read() fails Yizhuo
2019-09-30  4:45 ` Yizhuo
2019-10-04  7:02 ` Laurent Pinchart

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