[PATCH] drm/edid: Fix potential memory leak in edid_load()

[PATCH] drm/edid: Fix potential memory leak in edid_load()

[Alexey Khoroshilov]

Do not leak memory by updating pointer with potentially
NULL realloc return value.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
 drivers/gpu/drm/drm_edid_load.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 66d4a28..0303935 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -119,7 +119,7 @@ static int edid_load(struct drm_connector *connector, char *name,
 {
 	const struct firmware *fw;
 	struct platform_device *pdev;
-	u8 *fwdata = NULL, *edid;
+	u8 *fwdata = NULL, *edid, *new_edid;
 	int fwsize, expected;
 	int builtin = 0, err = 0;
 	int i, valid_extensions = 0;
@@ -195,12 +195,14 @@ static int edid_load(struct drm_connector *connector, char *name,
 		    "\"%s\" for connector \"%s\"\n", valid_extensions,
 		    edid[0x7e], name, connector_name);
 		edid[0x7e] = valid_extensions;
-		edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
+		new_edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
 		    GFP_KERNEL);
-		if (edid == NULL) {
+		if (new_edid == NULL) {
 			err = -ENOMEM;
+			kfree(edid);
 			goto relfw_out;
 		}
+		edid = new_edid;
 	}
 
 	connector->display_info.raw_edid = edid;
-- 
1.7.9.5

Re: [PATCH] drm/edid: Fix potential memory leak in edid_load()

[Carsten Emde]

On 08/07/2012 02:23 PM, Alexey Khoroshilov wrote:
> Do not leak memory by updating pointer with potentially
> NULL realloc return value.
>
> Found by Linux Driver Verification project (linuxtesting.org).
Thanks, Alexey!

Reviewed-by: Carsten Emde <C.Emde@osadl.org>

> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> ---
>   drivers/gpu/drm/drm_edid_load.c |    8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
> index 66d4a28..0303935 100644
> --- a/drivers/gpu/drm/drm_edid_load.c
> +++ b/drivers/gpu/drm/drm_edid_load.c
> @@ -119,7 +119,7 @@ static int edid_load(struct drm_connector *connector, char *name,
>   {
>   	const struct firmware *fw;
>   	struct platform_device *pdev;
> -	u8 *fwdata = NULL, *edid;
> +	u8 *fwdata = NULL, *edid, *new_edid;
>   	int fwsize, expected;
>   	int builtin = 0, err = 0;
>   	int i, valid_extensions = 0;
> @@ -195,12 +195,14 @@ static int edid_load(struct drm_connector *connector, char *name,
>   		    "\"%s\" for connector \"%s\"\n", valid_extensions,
>   		    edid[0x7e], name, connector_name);
>   		edid[0x7e] = valid_extensions;
> -		edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
> +		new_edid = krealloc(edid, (valid_extensions + 1) * EDID_LENGTH,
>   		    GFP_KERNEL);
> -		if (edid == NULL) {
> +		if (new_edid == NULL) {
>   			err = -ENOMEM;
> +			kfree(edid);
>   			goto relfw_out;
>   		}
> +		edid = new_edid;
>   	}
>
>   	connector->display_info.raw_edid = edid;