[PATCH] spi: Fix a memory leaking bug in wl1271_probe()

[PATCH] spi: Fix a memory leaking bug in wl1271_probe()

[Gen Zhang]

In wl1271_probe(), 'glue->core' is allocated by platform_device_alloc(),
when this allocation fails, ENOMEM is returned. However, 'pdev_data'
and 'glue' are allocated by devm_kzalloc() before 'glue->core'. When
platform_device_alloc() returns NULL, we should also free 'pdev_data'
and 'glue' before wl1271_probe() ends to prevent leaking memory.

Similarly, we shoulf free 'pdev_data' when 'glue' is NULL. And we should
free 'pdev_data' and 'glue' when 'glue->reg' is error and when 'ret' is
error.

Further, we should free 'glue->core', 'pdev_data' and 'glue' when this 
function normally ends to prevent leaking memory.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
---
diff --git a/drivers/net/wireless/ti/wlcore/spi.c b/drivers/net/wireless/ti/wlcore/spi.c
index 62ce54a..3a020bd 100644
--- a/drivers/net/wireless/ti/wlcore/spi.c
+++ b/drivers/net/wireless/ti/wlcore/spi.c
@@ -480,7 +480,7 @@ static int wl1271_probe(struct spi_device *spi)
 	struct wl12xx_spi_glue *glue;
 	struct wlcore_platdev_data *pdev_data;
 	struct resource res[1];
-	int ret;
+	int ret = -ENOMEM;
 
 	pdev_data = devm_kzalloc(&spi->dev, sizeof(*pdev_data), GFP_KERNEL);
 	if (!pdev_data)
@@ -491,7 +491,8 @@ static int wl1271_probe(struct spi_device *spi)
 	glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
 	if (!glue) {
 		dev_err(&spi->dev, "can't allocate glue\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_free1;
 	}
 
 	glue->dev = &spi->dev;
@@ -503,31 +504,35 @@ static int wl1271_probe(struct spi_device *spi)
 	spi->bits_per_word = 32;
 
 	glue->reg = devm_regulator_get(&spi->dev, "vwlan");
-	if (PTR_ERR(glue->reg) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
+	if (PTR_ERR(glue->reg) == -EPROBE_DEFER) {
+		ret = -EPROBE_DEFER;
+		goto out_free2;
+	}
 	if (IS_ERR(glue->reg)) {
 		dev_err(glue->dev, "can't get regulator\n");
-		return PTR_ERR(glue->reg);
+		ret = PTR_ERR(glue->reg);
+		goto out_free2;
 	}
 
 	ret = wlcore_probe_of(spi, glue, pdev_data);
 	if (ret) {
 		dev_err(glue->dev,
 			"can't get device tree parameters (%d)\n", ret);
-		return ret;
+		goto out_free2;
 	}
 
 	ret = spi_setup(spi);
 	if (ret < 0) {
 		dev_err(glue->dev, "spi_setup failed\n");
-		return ret;
+		goto out_free2;
 	}
 
 	glue->core = platform_device_alloc(pdev_data->family->name,
 					   PLATFORM_DEVID_AUTO);
 	if (!glue->core) {
 		dev_err(glue->dev, "can't allocate platform_device\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_free2;
 	}
 
 	glue->core->dev.parent = &spi->dev;
@@ -557,10 +562,18 @@ static int wl1271_probe(struct spi_device *spi)
 		goto out_dev_put;
 	}
 
+	platform_device_put(glue->core);
+	devm_kfree(&func->dev, glue);
+	devm_kfree(&func->dev, pdev_data);
 	return 0;
 
 out_dev_put:
 	platform_device_put(glue->core);
+out_free2:
+	devm_kfree(&func->dev, glue);
+out_free1:
+	devm_kfree(&func->dev, pdev_data);
+out:
 	return ret;
 }
 
---

Re: [PATCH] spi: Fix a memory leaking bug in wl1271_probe()

[Jon Hunter]

On 23/05/2019 15:30, Gen Zhang wrote:
> In wl1271_probe(), 'glue->core' is allocated by platform_device_alloc(),
> when this allocation fails, ENOMEM is returned. However, 'pdev_data'
> and 'glue' are allocated by devm_kzalloc() before 'glue->core'. When
> platform_device_alloc() returns NULL, we should also free 'pdev_data'
> and 'glue' before wl1271_probe() ends to prevent leaking memory.
> 
> Similarly, we shoulf free 'pdev_data' when 'glue' is NULL. And we should
> free 'pdev_data' and 'glue' when 'glue->reg' is error and when 'ret' is
> error.
> 
> Further, we should free 'glue->core', 'pdev_data' and 'glue' when this 
> function normally ends to prevent leaking memory.
> 
> Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
I have seen several of these patches now, and this is not correct. I
think you need to understand how devm_kzalloc() works.

Jon

-- 
nvpublic