2019-05-24 02:17:14

by Gen Zhang

Subject: [PATCH] pcm030-audio-fabric: Fix a memory leaking bug in pcm030_fabric_probe()

In pcm030_fabric_probe(), 'pdata->codec_device' is allocated by
platform_device_alloc(). When this allocation fails, ENOMEM is returned.
However, 'pdata' is allocated by devm_kzalloc() before this site. We
should free 'pdata' before function ends to prevent memory leaking.

Similarly, we should free 'pdata' when 'pdata->codec_device' is NULL.
And we should free 'pdata->codec_device' and 'pdata' when 'ret' is error
to prevent memory leaking.

Signed-off-by: Gen Zhang <[email protected]>
---
diff --git a/sound/soc/fsl/pcm030-audio-fabric.c b/sound/soc/fsl/pcm030-audio-fabric.c
index a7fe4ad..d2e6eae 100644
--- a/sound/soc/fsl/pcm030-audio-fabric.c
+++ b/sound/soc/fsl/pcm030-audio-fabric.c
@@ -72,29 +72,43 @@ static int pcm030_fabric_probe(struct platform_device *op)
platform_np = of_parse_phandle(np, "asoc-platform", 0);
if (!platform_np) {
dev_err(&op->dev, "ac97 not registered\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_free1;
}

for_each_card_prelinks(card, i, dai_link)
dai_link->platform_of_node = platform_np;

ret = request_module("snd-soc-wm9712");
- if (ret)
+ if (ret) {
dev_err(&op->dev, "request_module returned: %d\n", ret);
+ goto out_free1;
+ }

pdata->codec_device = platform_device_alloc("wm9712-codec", -1);
- if (!pdata->codec_device)
+ if (!pdata->codec_device) {
dev_err(&op->dev, "platform_device_alloc() failed\n");
+ ret = -ENOMEM;
+ goto out_free1;
+ }

ret = platform_device_add(pdata->codec_device);
- if (ret)
+ if (ret) {
dev_err(&op->dev, "platform_device_add() failed: %d\n", ret);
+ goto out_free2;
+ }

ret = snd_soc_register_card(card);
- if (ret)
+ if (ret) {
dev_err(&op->dev, "snd_soc_register_card() failed: %d\n", ret);
+ goto out_free2;
+ }

platform_set_drvdata(op, pdata);
+out_free2:
+ platform_device_put(pdata->codec_device);
+out_free1:
+ devm_kfree(&op->dev, pdata);

return ret;
}
---

2019-05-24 09:32:17

by Jon Hunter

Subject: Re: [PATCH] pcm030-audio-fabric: Fix a memory leaking bug in pcm030_fabric_probe()

On 24/05/2019 03:12, Gen Zhang wrote:
> In pcm030_fabric_probe(), 'pdata->codec_device' is allocated by
> platform_device_alloc(). When this allocation fails, ENOMEM is returned.
> However, 'pdata' is allocated by devm_kzalloc() before this site. We
> should free 'pdata' before function ends to prevent memory leaking.
>
> Similarly, we should free 'pdata' when 'pdata->codec_device' is NULL.
> And we should free 'pdata->codec_device' and 'pdata' when 'ret' is error
> to prevent memory leaking.
>
> 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