[PATCH] can: sun4i_can: Fix clk leak in sun4ican_probe()

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

In sun4ican_probe(), the clock is obtained with of_clk_get(), which
returns a reference that must be released with clk_put().  If
platform_get_irq(), devm_platform_ioremap_resource(), alloc_candev()
or register_candev() fails, the reference is never released, leaking
the clock.

Fix this by adding an exit_put_clk label that releases the clock and
jumping to it from all error paths after the of_clk_get() call.

Fixes: 0738eff14d81 ("can: Allwinner A10/A20 CAN Controller support - Kernel module")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/net/can/sun4i_can.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
index af52285d5a4e..311526107ed8 100644
--- a/drivers/net/can/sun4i_can.c
+++ b/drivers/net/can/sun4i_can.c
@@ -854,13 +854,13 @@ static int sun4ican_probe(struct platform_device *pdev)
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		err = -ENODEV;
-		goto exit;
+		goto exit_put_clk;
 	}
 
 	addr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(addr)) {
 		err = PTR_ERR(addr);
-		goto exit;
+		goto exit_put_clk;
 	}
 
 	dev = alloc_candev(sizeof(struct sun4ican_priv), 1);
@@ -868,7 +868,7 @@ static int sun4ican_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev,
 			"could not allocate memory for CAN device\n");
 		err = -ENOMEM;
-		goto exit;
+		goto exit_put_clk;
 	}
 
 	dev->netdev_ops = &sun4ican_netdev_ops;
@@ -908,6 +908,8 @@ static int sun4ican_probe(struct platform_device *pdev)
 
 exit_free:
 	free_candev(dev);
+exit_put_clk:
+	clk_put(clk);
 exit:
 	return err;
 }
-- 
2.34.1