[PATCH v3] i2c: sun6i-p2wi: Fix device node reference leak in p2wi_probe

[PATCH v3] i2c: sun6i-p2wi: Fix device node reference leak in p2wi_probe

[Uday Khare]

In p2wi_probe(), the device node reference obtained via
of_get_next_available_child() is stored in childnp. This reference is
never released, causing a device node reference leak.

Fix this by calling of_node_put(childnp) on both the error and success
paths.

Fixes: 3e833490fae5 ("i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support")
Signed-off-by: Uday Khare <udaykhare77@gmail.com>
---
v3:
- Revert back to manual of_node_put() because the function uses goto-based
  error handling, and mixing the two styles is discouraged (reported by
  Sashiko-bot).
v2:
- Use __free(device_node) and include <linux/cleanup.h> to automate the device
  node reference cleanup instead of manually calling of_node_put() on error and
  success paths (suggested by Chen-Yu Tsai).

 drivers/i2c/busses/i2c-sun6i-p2wi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sun6i-p2wi.c b/drivers/i2c/busses/i2c-sun6i-p2wi.c
index dffbe776a195..7c0239f8937e 100644
--- a/drivers/i2c/busses/i2c-sun6i-p2wi.c
+++ b/drivers/i2c/busses/i2c-sun6i-p2wi.c
@@ -184,7 +184,6 @@ static int p2wi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
-	struct device_node *childnp;
 	unsigned long parent_clk_freq;
 	u32 clk_freq = I2C_MAX_STANDARD_MODE_FREQ;
 	struct p2wi *p2wi;
@@ -217,14 +216,19 @@ static int p2wi_probe(struct platform_device *pdev)
 	 * In this case the target_addr is set to -1 and won't be checked when
 	 * launching a P2WI transfer.
 	 */
+	struct device_node *childnp;
+
 	childnp = of_get_next_available_child(np, NULL);
 	if (childnp) {
 		ret = of_property_read_u32(childnp, "reg", &target_addr);
-		if (ret)
+		if (ret) {
+			of_node_put(childnp);
 			return dev_err_probe(dev, -EINVAL,
 					     "invalid target address on node %pOF\n", childnp);
+		}
 
 		p2wi->target_addr = target_addr;
+		of_node_put(childnp);
 	}
 
 	p2wi->regs = devm_platform_ioremap_resource(pdev, 0);
-- 
2.54.0