* [PATCH v2] leds: ns2: Add of_node_put() before return
@ 2019-07-16 7:24 Nishka Dasgupta
2019-07-16 18:21 ` Jacek Anaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Nishka Dasgupta @ 2019-07-16 7:24 UTC (permalink / raw)
To: jacek.anaszewski, pavel, dmurphy, linux-leds; +Cc: Nishka Dasgupta
Each iteration of for_each_child_of_node puts the previous node, but in
the case of a return from the middle of the loop, there is no put, thus
causing a memory leak. Hence create a new label, err_node_put, that puts
the previous node before returning the required value. Edit the mid-loop
return sites to instead go to this new label.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
---
Changes in v2:
- Put the of_node_put statement under a label instead of at each return
site.
- Modify subject line to reflect previous patches on this driver.
drivers/leds/leds-ns2.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/leds/leds-ns2.c b/drivers/leds/leds-ns2.c
index f92e2c07c1c6..83cdce0f801a 100644
--- a/drivers/leds/leds-ns2.c
+++ b/drivers/leds/leds-ns2.c
@@ -264,11 +264,11 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
ret = of_get_named_gpio(child, "cmd-gpio", 0);
if (ret < 0)
- return ret;
+ goto err_node_put;
led->cmd = ret;
ret = of_get_named_gpio(child, "slow-gpio", 0);
if (ret < 0)
- return ret;
+ goto err_node_put;
led->slow = ret;
ret = of_property_read_string(child, "label", &string);
led->name = (ret == 0) ? string : child->name;
@@ -281,7 +281,8 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
if (ret < 0 || ret % 3) {
dev_err(dev,
"Missing or malformed modes-map property\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto err_node_put;
}
num_modes = ret / 3;
@@ -289,8 +290,10 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
num_modes,
sizeof(struct ns2_led_modval),
GFP_KERNEL);
- if (!modval)
- return -ENOMEM;
+ if (!modval) {
+ ret = -ENOMEM;
+ goto err_node_put;
+ }
for (i = 0; i < num_modes; i++) {
of_property_read_u32_index(child,
@@ -314,6 +317,10 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
pdata->num_leds = num_leds;
return 0;
+
+err_node_put:
+ of_node_put(child);
+ return ret;
}
static const struct of_device_id of_ns2_leds_match[] = {
--
2.19.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] leds: ns2: Add of_node_put() before return
2019-07-16 7:24 [PATCH v2] leds: ns2: Add of_node_put() before return Nishka Dasgupta
@ 2019-07-16 18:21 ` Jacek Anaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Jacek Anaszewski @ 2019-07-16 18:21 UTC (permalink / raw)
To: Nishka Dasgupta, pavel, dmurphy, linux-leds
Hi Nishka,
Thank you for the update.
On 7/16/19 9:24 AM, Nishka Dasgupta wrote:
> Each iteration of for_each_child_of_node puts the previous node, but in
> the case of a return from the middle of the loop, there is no put, thus
> causing a memory leak. Hence create a new label, err_node_put, that puts
> the previous node before returning the required value. Edit the mid-loop
> return sites to instead go to this new label.
> Issue found with Coccinelle.
>
> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
> ---
> Changes in v2:
> - Put the of_node_put statement under a label instead of at each return
> site.
> - Modify subject line to reflect previous patches on this driver.
>
> drivers/leds/leds-ns2.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/leds/leds-ns2.c b/drivers/leds/leds-ns2.c
> index f92e2c07c1c6..83cdce0f801a 100644
> --- a/drivers/leds/leds-ns2.c
> +++ b/drivers/leds/leds-ns2.c
> @@ -264,11 +264,11 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
>
> ret = of_get_named_gpio(child, "cmd-gpio", 0);
> if (ret < 0)
> - return ret;
> + goto err_node_put;
> led->cmd = ret;
> ret = of_get_named_gpio(child, "slow-gpio", 0);
> if (ret < 0)
> - return ret;
> + goto err_node_put;
> led->slow = ret;
> ret = of_property_read_string(child, "label", &string);
> led->name = (ret == 0) ? string : child->name;
> @@ -281,7 +281,8 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
> if (ret < 0 || ret % 3) {
> dev_err(dev,
> "Missing or malformed modes-map property\n");
> - return -EINVAL;
> + ret = -EINVAL;
> + goto err_node_put;
> }
>
> num_modes = ret / 3;
> @@ -289,8 +290,10 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
> num_modes,
> sizeof(struct ns2_led_modval),
> GFP_KERNEL);
> - if (!modval)
> - return -ENOMEM;
> + if (!modval) {
> + ret = -ENOMEM;
> + goto err_node_put;
> + }
>
> for (i = 0; i < num_modes; i++) {
> of_property_read_u32_index(child,
> @@ -314,6 +317,10 @@ ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
> pdata->num_leds = num_leds;
>
> return 0;
> +
> +err_node_put:
> + of_node_put(child);
> + return ret;
Now we're getting build break here since ret is declared only
inside the loop. I moved ret declaration to the top of the function
and applied. Thanks.
> }
>
> static const struct of_device_id of_ns2_leds_match[] = {
>
--
Best regards,
Jacek Anaszewski
^ permalink raw reply [flat|nested] 2+ messages in thread
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