[PATCH can-next 2/2] net: m_can: Fix freeing of can device from peripherials

[Dan Murphy]

Fix leaking netdev device from peripherial devices.  The call to
allocate the netdev device is made from and managed by the peripherial.

Create a common function that peripherials can call to free the netdev
device when failures occur.

Fixes: d42f4e1d06d9 ("can: m_can: Create a m_can platform framework")
Reported-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---
 drivers/net/can/m_can/m_can.c          |  9 ++++---
 drivers/net/can/m_can/m_can.h          |  2 ++
 drivers/net/can/m_can/m_can_platform.c | 21 ++++++++++------
 drivers/net/can/m_can/tcan4x5x.c       | 35 ++++++++++++++++----------
 4 files changed, 43 insertions(+), 24 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 5794be1ef3ef..b1eca4aa59f8 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1796,6 +1796,12 @@ struct m_can_classdev *m_can_class_allocate_dev(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
 
+void m_can_class_free_dev(struct net_device *net)
+{
+	free_candev(net);
+}
+EXPORT_SYMBOL_GPL(m_can_class_free_dev);
+
 int m_can_class_register(struct m_can_classdev *m_can_dev)
 {
 	int ret;
@@ -1834,7 +1840,6 @@ int m_can_class_register(struct m_can_classdev *m_can_dev)
 	if (ret) {
 		if (m_can_dev->pm_clock_support)
 			pm_runtime_disable(m_can_dev->dev);
-		free_candev(m_can_dev->net);
 	}
 
 	return ret;
@@ -1892,8 +1897,6 @@ void m_can_class_unregister(struct m_can_classdev *m_can_dev)
 	unregister_candev(m_can_dev->net);
 
 	m_can_clk_stop(m_can_dev);
-
-	free_candev(m_can_dev->net);
 }
 EXPORT_SYMBOL_GPL(m_can_class_unregister);
 
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index c20a716b14cc..fa6dba3a893c 100644
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -97,6 +97,7 @@ struct m_can_classdev {
 };
 
 struct m_can_classdev *m_can_class_allocate_dev(struct device *dev);
+void m_can_class_free_dev(struct net_device *net);
 int m_can_class_register(struct m_can_classdev *cdev);
 void m_can_class_unregister(struct m_can_classdev *cdev);
 void m_can_init_ram(struct m_can_classdev *priv);
@@ -104,4 +105,5 @@ void m_can_config_endisable(struct m_can_classdev *priv, bool enable);
 
 int m_can_class_suspend(struct device *dev);
 int m_can_class_resume(struct device *dev);
+
 #endif	/* _CAN_M_H_ */
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 8bd459317eba..275f87931529 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -86,34 +86,36 @@ static int m_can_plat_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
+	if (!priv) {
+		ret = -ENOMEM;
+		goto probe_fail;
+	}
 
 	mcan_class->device_data = priv;
 
 	ret = m_can_plat_get_clocks(priv, mcan_class);
 	if (ret)
-		return ret;
+		goto probe_fail;
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
 	addr = devm_ioremap_resource(&pdev->dev, res);
 	irq = platform_get_irq_byname(pdev, "int0");
 	if (IS_ERR(addr) || irq < 0) {
 		ret = -EINVAL;
-		goto failed_ret;
+		goto probe_fail;
 	}
 
 	/* message ram could be shared */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
 	if (!res) {
 		ret = -ENODEV;
-		goto failed_ret;
+		goto probe_fail;
 	}
 
 	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 	if (!mram_addr) {
 		ret = -ENOMEM;
-		goto failed_ret;
+		goto probe_fail;
 	}
 
 	priv->base = addr;
@@ -132,9 +134,10 @@ static int m_can_plat_probe(struct platform_device *pdev)
 
 	m_can_init_ram(mcan_class);
 
-	ret = m_can_class_register(mcan_class);
+	return m_can_class_register(mcan_class);
 
-failed_ret:
+probe_fail:
+	m_can_class_free_dev(mcan_class->net);
 	return ret;
 }
 
@@ -155,6 +158,8 @@ static int m_can_plat_remove(struct platform_device *pdev)
 
 	m_can_class_unregister(mcan_class);
 
+	m_can_class_free_dev(mcan_class->net);
+
 	platform_set_drvdata(pdev, NULL);
 
 	return 0;
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
index 37d53ecc560b..0b6acc3caf25 100644
--- a/drivers/net/can/m_can/tcan4x5x.c
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -463,20 +463,26 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
+	if (!priv) {
+		ret = -ENOMEM;
+		goto probe_fail;
+	}
 
 	priv->power = devm_regulator_get_optional(&spi->dev, "vsup");
-	if (PTR_ERR(priv->power) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-	else
+	if (PTR_ERR(priv->power) == -EPROBE_DEFER) {
+		ret = -EPROBE_DEFER;
+		goto probe_fail;
+	} else {
 		priv->power = NULL;
+	}
 
 	mcan_class->device_data = priv;
 
 	freq = tcan4x5x_get_clock(priv, mcan_class);
-	if (freq < 0)
-		return freq;
+	if (freq < 0) {
+		ret = -EINVAL;
+		goto probe_fail;
+	}
 
 	priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
 	priv->mram_start = TCAN4X5X_MRAM_START;
@@ -498,32 +504,33 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
 	spi->bits_per_word = 32;
 	ret = spi_setup(spi);
 	if (ret)
-		return ret;
+		goto probe_fail;
 
 	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
 					&spi->dev, &tcan4x5x_regmap);
 
 	ret = tcan4x5x_power_enable(priv->power, 1);
 	if (ret)
-		return ret;
+		goto probe_fail;
 
 	ret = tcan4x5x_get_gpios(mcan_class);
 	if (ret)
-		goto out_power;
+		goto probe_fail;
 
 	ret = tcan4x5x_init(mcan_class);
 	if (ret)
-		goto out_power;
+		goto probe_fail;
 
 	ret = m_can_class_register(mcan_class);
 	if (ret)
-		goto out_power;
+		goto probe_fail;
 
 	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
 	return 0;
 
-out_power:
+probe_fail:
 	tcan4x5x_power_enable(priv->power, 0);
+	m_can_class_free_dev(mcan_class->net);
 	dev_err(&spi->dev, "Probe failed, err=%d\n", ret);
 	return ret;
 }
@@ -536,6 +543,8 @@ static int tcan4x5x_can_remove(struct spi_device *spi)
 
 	m_can_class_unregister(priv->mcan_dev);
 
+	m_can_class_free_dev(priv->mcan_dev->net);
+
 	return 0;
 }
 
-- 
2.25.0