[PATCH v4 0/1] libnvdimm: fix memory leaks in of_pmem.c

[PATCH v4 0/1] libnvdimm: fix memory leaks in of_pmem.c

[Zhen Lei]

v3 --> v4
1. Merge patch 1 and 2 into one:
   https://lkml.org/lkml/2020/8/19/1464		Patch 1
   https://lkml.org/lkml/2020/8/19/1468		Patch 2
2. The part from patch 1 was reviewed by Oliver O'Halloran <oohall@gmail.com>

Zhen Lei (1):
  libnvdimm: fix memory leaks in of_pmem.c

 drivers/nvdimm/of_pmem.c | 7 +++++++
 1 file changed, 7 insertions(+)

-- 
1.8.3

[PATCH v4 1/1] libnvdimm: fix memory leaks in of_pmem.c

[Zhen Lei]

Currently, in the last error path of of_pmem_region_probe() and in
of_pmem_region_remove(), free the memory allocated by kstrdup() is
missing. Add kfree(priv->bus_desc.provider_name) to fix it.

In addition, add a sanity check to kstrdup() to prevent a
NULL-pointer dereference.

Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
---
 drivers/nvdimm/of_pmem.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
index 10dbdcdfb9ce913..13c4c274ca6ea88 100644
--- a/drivers/nvdimm/of_pmem.c
+++ b/drivers/nvdimm/of_pmem.c
@@ -31,11 +31,17 @@ static int of_pmem_region_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
+	if (!priv->bus_desc.provider_name) {
+		kfree(priv);
+		return -ENOMEM;
+	}
+
 	priv->bus_desc.module = THIS_MODULE;
 	priv->bus_desc.of_node = np;
 
 	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
 	if (!bus) {
+		kfree(priv->bus_desc.provider_name);
 		kfree(priv);
 		return -ENODEV;
 	}
@@ -83,6 +89,7 @@ static int of_pmem_region_remove(struct platform_device *pdev)
 	struct of_pmem_private *priv = platform_get_drvdata(pdev);
 
 	nvdimm_bus_unregister(priv->bus);
+	kfree(priv->bus_desc.provider_name);
 	kfree(priv);
 
 	return 0;
-- 
1.8.3

Re: [PATCH v4 0/1] libnvdimm: fix memory leaks in of_pmem.c

[Leizhen (ThunderTown)]

On 2020/9/1 18:14, Markus Elfring wrote:
>> v3 --> v4
>> 1. Merge patch 1 and 2 into one:
> 
> How do you think about to omit a cover letter for a single patch?

After all, the code hasn't changed except this merge.

> 
> Regards,
> Markus
> 
> 

Re: [PATCH v4 1/1] libnvdimm: fix memory leaks in of_pmem.c

[Leizhen (ThunderTown)]

Hi, all:
  Is this patch acceptable?


On 2020/9/1 16:14, Zhen Lei wrote:
> Currently, in the last error path of of_pmem_region_probe() and in
> of_pmem_region_remove(), free the memory allocated by kstrdup() is
> missing. Add kfree(priv->bus_desc.provider_name) to fix it.
> 
> In addition, add a sanity check to kstrdup() to prevent a
> NULL-pointer dereference.
> 
> Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
> ---
>  drivers/nvdimm/of_pmem.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
> index 10dbdcdfb9ce913..13c4c274ca6ea88 100644
> --- a/drivers/nvdimm/of_pmem.c
> +++ b/drivers/nvdimm/of_pmem.c
> @@ -31,11 +31,17 @@ static int of_pmem_region_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
> +	if (!priv->bus_desc.provider_name) {
> +		kfree(priv);
> +		return -ENOMEM;
> +	}
> +
>  	priv->bus_desc.module = THIS_MODULE;
>  	priv->bus_desc.of_node = np;
>  
>  	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
>  	if (!bus) {
> +		kfree(priv->bus_desc.provider_name);
>  		kfree(priv);
>  		return -ENODEV;
>  	}
> @@ -83,6 +89,7 @@ static int of_pmem_region_remove(struct platform_device *pdev)
>  	struct of_pmem_private *priv = platform_get_drvdata(pdev);
>  
>  	nvdimm_bus_unregister(priv->bus);
> +	kfree(priv->bus_desc.provider_name);
>  	kfree(priv);
>  
>  	return 0;
>