2023-06-22 14:42:01

by Jiasheng Jiang

Subject: [PATCH] libnvdimm/of_pmem: Replace kstrdup with devm_kstrdup and add check

Replace kstrdup() with devm_kstrdup() to avoid memory leak and
add check for the return value of the devm_kstrdup() to avoid
NULL pointer dereference

Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
Signed-off-by: Jiasheng Jiang <[email protected]>
---
drivers/nvdimm/of_pmem.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
index 10dbdcdfb9ce..5106dfe0147b 100644
--- a/drivers/nvdimm/of_pmem.c
+++ b/drivers/nvdimm/of_pmem.c
@@ -30,7 +30,12 @@ static int of_pmem_region_probe(struct platform_device *pdev)
if (!priv)
return -ENOMEM;

- priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
+ priv->bus_desc.provider_name = devm_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;

--
2.25.1

2023-06-23 18:33:12

by Ira Weiny

Subject: Re: [PATCH] libnvdimm/of_pmem: Replace kstrdup with devm_kstrdup and add check

Jiasheng Jiang wrote:
> Replace kstrdup() with devm_kstrdup() to avoid memory leak and
> add check for the return value of the devm_kstrdup() to avoid
> NULL pointer dereference
>
> Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
> Signed-off-by: Jiasheng Jiang <[email protected]>

V2? references to the first fix and review?

> ---
> drivers/nvdimm/of_pmem.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
> index 10dbdcdfb9ce..5106dfe0147b 100644
> --- a/drivers/nvdimm/of_pmem.c
> +++ b/drivers/nvdimm/of_pmem.c
> @@ -30,7 +30,12 @@ static int of_pmem_region_probe(struct platform_device *pdev)
> if (!priv)
> return -ENOMEM;
>
> - priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
> + priv->bus_desc.provider_name = devm_kstrdup(pdev->name, GFP_KERNEL);

Again, thanks for finding and trying to fix this but you did not even compile
test this. :-(

/**
* devm_kstrdup - Allocate resource managed space and
* copy an existing string into that.
* @dev: Device to allocate memory for
* @s: the string to duplicate
* @gfp: the GFP mask used in the devm_kmalloc() call when
* allocating memory
* RETURNS:
* Pointer to allocated string on success, NULL on failure.
*/
char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
^^^^^^^^^^^^^^^^^^
??????????????????

Ira

> + if (!priv->bus_desc.provider_name) {
> + kfree(priv);
> + return -ENOMEM;
> + }
> +
> priv->bus_desc.module = THIS_MODULE;
> priv->bus_desc.of_node = np;
>
> --
> 2.25.1
>