[PATCH] leds: spi-byte: fix unbalanced of_node_get()/of_node_put()

From: Wei Yongjun
Date: Mon Sep 05 2022 - 11:13:44 EST


From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>

Enabling CONFIG_OF_DYNAMIC triggers the following error at device remove:

OF: ERROR: memory leak, expected refcount 1 instead of 2, \
of_node_get()/of_node_put() unbalanced - destroy cset entry: \
attach overlay node /spi/led-controller@0/led

of_get_next_available_child() is used to get child node with refcount
incremented in spi_byte_probe(), but missing of_node_put() on it when
done. This patch fix it.

Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
---
drivers/leds/leds-spi-byte.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/leds-spi-byte.c b/drivers/leds/leds-spi-byte.c
index 9d23dc9e7639..eaad227b4542 100644
--- a/drivers/leds/leds-spi-byte.c
+++ b/drivers/leds/leds-spi-byte.c
@@ -91,12 +91,12 @@ static int spi_byte_probe(struct spi_device *spi)
dev_err(dev, "Device must have exactly one LED sub-node.");
return -EINVAL;
}
- child = of_get_next_available_child(dev_of_node(dev), NULL);

led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;

+ child = of_get_next_available_child(dev_of_node(dev), NULL);
of_property_read_string(child, "label", &name);
strlcpy(led->name, name, sizeof(led->name));
led->spi = spi;
@@ -113,10 +113,12 @@ static int spi_byte_probe(struct spi_device *spi)
led->ldev.brightness = led->ldev.max_brightness;
} else if (strcmp(state, "off")) {
/* all other cases except "off" */
+ of_node_put(child);
dev_err(dev, "default-state can only be 'on' or 'off'");
return -EINVAL;
}
}
+ of_node_put(child);
spi_byte_brightness_set_blocking(&led->ldev,
led->ldev.brightness);

--
2.34.1