[PATCH] i2c: pnx: Fix of_node reference leak in i2c_pnx_probe()

[Wentao Liang <vulab@iscas.ac.cn>]

The device node reference taken with of_node_get() for the adapter
device is never released: the early probe error paths return without
dropping it, and neither the late error paths nor i2c_pnx_remove() put
it back. The i2c core does not release the adapter device's of_node
either.

Route the clock, I/O mapping and clock-enable error paths to a common
label that drops the node reference, and drop the reference after
i2c_del_adapter() in the remove path.

Fixes: b41a216dafe4 ("i2c: Add device tree support to i2c-pnx.c")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/i2c/busses/i2c-pnx.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c
index 8daa0008bd05..b2a686b132ea 100644
--- a/drivers/i2c/busses/i2c-pnx.c
+++ b/drivers/i2c/busses/i2c-pnx.c
@@ -644,20 +644,24 @@ static int i2c_pnx_probe(struct platform_device *pdev)
 	}
 #endif
 	alg_data->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(alg_data->clk))
-		return PTR_ERR(alg_data->clk);
+	if (IS_ERR(alg_data->clk)) {
+		ret = PTR_ERR(alg_data->clk);
+		goto err_of_node;
+	}
 
 	snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
 		 "%s", pdev->name);
 
 	/* Register I/O resource */
 	alg_data->ioaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
-	if (IS_ERR(alg_data->ioaddr))
-		return PTR_ERR(alg_data->ioaddr);
+	if (IS_ERR(alg_data->ioaddr)) {
+		ret = PTR_ERR(alg_data->ioaddr);
+		goto err_of_node;
+	}
 
 	ret = clk_prepare_enable(alg_data->clk);
 	if (ret)
-		return ret;
+		goto err_of_node;
 
 	freq = clk_get_rate(alg_data->clk);
 
@@ -707,6 +711,8 @@ static int i2c_pnx_probe(struct platform_device *pdev)
 
 out_clock:
 	clk_disable_unprepare(alg_data->clk);
+err_of_node:
+	of_node_put(alg_data->adapter.dev.of_node);
 	return ret;
 }
 
@@ -716,6 +722,7 @@ static void i2c_pnx_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&alg_data->adapter);
 	clk_disable_unprepare(alg_data->clk);
+	of_node_put(alg_data->adapter.dev.of_node);
 }
 
 #ifdef CONFIG_OF
-- 
2.34.1