2019-05-23 14:32:48

by Gen Zhang

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

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 <[email protected]>
---
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;
}

---

2019-05-24 09:44:10

by Jon Hunter

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

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 <[email protected]>
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