[PATCH] pinctrl: freescale: imx: Add of_node_put() before return

[PATCH] pinctrl: freescale: imx: Add of_node_put() before return

[Nishka Dasgupta]

Each iteration of for_each_child_of_node() puts the previous node;
however, in the case of a return from the middle of the loop, there is no
put, thus causing a memory leak. Hence put of_node_put() statements as
required before two mid-loop return statements.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
---
 drivers/pinctrl/freescale/pinctrl-imx.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
index 83ff9532bae6..9f42036c5fbb 100644
--- a/drivers/pinctrl/freescale/pinctrl-imx.c
+++ b/drivers/pinctrl/freescale/pinctrl-imx.c
@@ -672,8 +672,10 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
 
 		grp = devm_kzalloc(ipctl->dev, sizeof(struct group_desc),
 				   GFP_KERNEL);
-		if (!grp)
+		if (!grp) {
+			of_node_put(child);
 			return -ENOMEM;
+		}
 
 		mutex_lock(&ipctl->mutex);
 		radix_tree_insert(&pctl->pin_group_tree,
@@ -697,12 +699,17 @@ static bool imx_pinctrl_dt_is_flat_functions(struct device_node *np)
 	struct device_node *pinctrl_np;
 
 	for_each_child_of_node(np, function_np) {
-		if (of_property_read_bool(function_np, "fsl,pins"))
+		if (of_property_read_bool(function_np, "fsl,pins")) {
+			of_node_put(function_np);
 			return true;
+		}
 
 		for_each_child_of_node(function_np, pinctrl_np) {
-			if (of_property_read_bool(pinctrl_np, "fsl,pins"))
+			if (of_property_read_bool(pinctrl_np, "fsl,pins")) {
+				of_node_put(pinctrl_np);
+				of_node_put(function_np);
 				return false;
+			}
 		}
 	}
 
-- 
2.19.1

Re: [PATCH] pinctrl: freescale: imx: Add of_node_put() before return

[Philipp Zabel]

On Thu, 2019-08-08 at 13:17 +0530, Nishka Dasgupta wrote:
> Each iteration of for_each_child_of_node() puts the previous node;
> however, in the case of a return from the middle of the loop, there is no
> put, thus causing a memory leak. Hence put of_node_put() statements as
> required before two mid-loop return statements.
> Issue found with Coccinelle.
> 
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
> ---
>  drivers/pinctrl/freescale/pinctrl-imx.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c
> index 83ff9532bae6..9f42036c5fbb 100644
> --- a/drivers/pinctrl/freescale/pinctrl-imx.c
> +++ b/drivers/pinctrl/freescale/pinctrl-imx.c
> @@ -672,8 +672,10 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
>  
>  		grp = devm_kzalloc(ipctl->dev, sizeof(struct group_desc),
>  				   GFP_KERNEL);

This looks to me like it could just allocate an array of struct
group_desc upfront, just like the group_names array. Same for the
functions in imx_pinctrl_probe_dt(). Not an issue with this patch
though.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

> -		if (!grp)
> +		if (!grp) {
> +			of_node_put(child);
>  			return -ENOMEM;
> +		}
>  
>  		mutex_lock(&ipctl->mutex);
>  		radix_tree_insert(&pctl->pin_group_tree,
> @@ -697,12 +699,17 @@ static bool imx_pinctrl_dt_is_flat_functions(struct device_node *np)
>  	struct device_node *pinctrl_np;
>  
>  	for_each_child_of_node(np, function_np) {
> -		if (of_property_read_bool(function_np, "fsl,pins"))
> +		if (of_property_read_bool(function_np, "fsl,pins")) {
> +			of_node_put(function_np);
>  			return true;
> +		}
>  
>  		for_each_child_of_node(function_np, pinctrl_np) {
> -			if (of_property_read_bool(pinctrl_np, "fsl,pins"))
> +			if (of_property_read_bool(pinctrl_np, "fsl,pins")) {
> +				of_node_put(pinctrl_np);
> +				of_node_put(function_np);
>  				return false;
> +			}
>  		}
>  	}
>  

Re: [PATCH] pinctrl: freescale: imx: Add of_node_put() before return

[Linus Walleij]

On Thu, Aug 8, 2019 at 9:47 AM Nishka Dasgupta <nishkadg.linux@gmail.com> wrote:

> Each iteration of for_each_child_of_node() puts the previous node;
> however, in the case of a return from the middle of the loop, there is no
> put, thus causing a memory leak. Hence put of_node_put() statements as
> required before two mid-loop return statements.
> Issue found with Coccinelle.
>
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>

Patch applied with Philipp's ACK.

Yours,
Linus Walleij