[PATCH] misc: tps6594-pfsm: Add NULL check in tps6594_pfsm_probe

[PATCH] misc: tps6594-pfsm: Add NULL check in tps6594_pfsm_probe

[Charles Han]

devm_kasprintf() can return a NULL pointer on failure,but this
returned value in tps6594_pfsm_probe() is not checked.
Add NULL check in tps6594_pfsm_probe(), to handle kernel NULL
pointer dereference error.

Fixes: a0df3ef087f8 ("misc: tps6594-pfsm: Add driver for TI TPS6594 PFSM")
Signed-off-by: Charles Han <hanchunchao@inspur.com>
---
 drivers/misc/tps6594-pfsm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/misc/tps6594-pfsm.c b/drivers/misc/tps6594-pfsm.c
index 0a24ce44cc37..05c4e081a8d2 100644
--- a/drivers/misc/tps6594-pfsm.c
+++ b/drivers/misc/tps6594-pfsm.c
@@ -281,6 +281,11 @@ static int tps6594_pfsm_probe(struct platform_device *pdev)
 	pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
 	pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
 					    tps->chip_id, tps->reg);
+	if (!pfsm->miscdev.name) {
+		devm_kfree(dev, pfsm);
+		return -ENOMEM;
+	}
+
 	pfsm->miscdev.fops = &tps6594_pfsm_fops;
 	pfsm->miscdev.parent = dev->parent;
 	pfsm->chip_id = tps->chip_id;
-- 
2.43.0

Re: [PATCH] misc: tps6594-pfsm: Add NULL check in tps6594_pfsm_probe

[Arnd Bergmann]

On Thu, Apr 10, 2025, at 12:52, Charles Han wrote:
> +	if (!pfsm->miscdev.name) {
> +		devm_kfree(dev, pfsm);
> +		return -ENOMEM;
> +	}

Since this is the probe function, you don't need to call devm_kfree()
but just let devres take care of it.

     Arnd

Re: [PATCH] misc: tps6594-pfsm: Add NULL check in tps6594_pfsm_probe

[Greg KH]

On Thu, Apr 10, 2025 at 06:52:53PM +0800, Charles Han wrote:
> devm_kasprintf() can return a NULL pointer on failure,but this
> returned value in tps6594_pfsm_probe() is not checked.
> Add NULL check in tps6594_pfsm_probe(), to handle kernel NULL
> pointer dereference error.
> 
> Fixes: a0df3ef087f8 ("misc: tps6594-pfsm: Add driver for TI TPS6594 PFSM")
> Signed-off-by: Charles Han <hanchunchao@inspur.com>
> ---
>  drivers/misc/tps6594-pfsm.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/misc/tps6594-pfsm.c b/drivers/misc/tps6594-pfsm.c
> index 0a24ce44cc37..05c4e081a8d2 100644
> --- a/drivers/misc/tps6594-pfsm.c
> +++ b/drivers/misc/tps6594-pfsm.c
> @@ -281,6 +281,11 @@ static int tps6594_pfsm_probe(struct platform_device *pdev)
>  	pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
>  	pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
>  					    tps->chip_id, tps->reg);
> +	if (!pfsm->miscdev.name) {
> +		devm_kfree(dev, pfsm);
> +		return -ENOMEM;
> +	}

How was this found and tested?

thanks,

greg k-h

Re: [PATCH] misc: tps6594-pfsm: Add NULL check in tps6594_pfsm_probe

[Greg KH]

On Thu, Apr 10, 2025 at 06:52:53PM +0800, Charles Han wrote:
> devm_kasprintf() can return a NULL pointer on failure,but this
> returned value in tps6594_pfsm_probe() is not checked.
> Add NULL check in tps6594_pfsm_probe(), to handle kernel NULL
> pointer dereference error.
> 
> Fixes: a0df3ef087f8 ("misc: tps6594-pfsm: Add driver for TI TPS6594 PFSM")
> Signed-off-by: Charles Han <hanchunchao@inspur.com>
> ---
>  drivers/misc/tps6594-pfsm.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/misc/tps6594-pfsm.c b/drivers/misc/tps6594-pfsm.c
> index 0a24ce44cc37..05c4e081a8d2 100644
> --- a/drivers/misc/tps6594-pfsm.c
> +++ b/drivers/misc/tps6594-pfsm.c
> @@ -281,6 +281,11 @@ static int tps6594_pfsm_probe(struct platform_device *pdev)
>  	pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
>  	pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
>  					    tps->chip_id, tps->reg);
> +	if (!pfsm->miscdev.name) {
> +		devm_kfree(dev, pfsm);
> +		return -ENOMEM;
> +	}
> +
>  	pfsm->miscdev.fops = &tps6594_pfsm_fops;
>  	pfsm->miscdev.parent = dev->parent;
>  	pfsm->chip_id = tps->chip_id;
> -- 
> 2.43.0
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
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