[v1] drivers/misc: Add NULL check in aspeed_lpc_enable_snoop

[PATCH] drivers/misc: Add NULL check in aspeed_lpc_enable_snoop

Posted by Henry Martin 8 months, 3 weeks ago

When devm_kasprintf() fails, it returns a NULL pointer. However, this return value is not properly checked in the function aspeed_lpc_enable_snoop.

A NULL check should be added after the devm_kasprintf() to prevent potential NULL pointer dereference error.

Fixes: 3772e5da44542 ("Aspeed LPC snoop output using misc chardev")

Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
---
 drivers/soc/aspeed/aspeed-lpc-snoop.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
index 9ab5ba9cf1d6..376b3a910797 100644
--- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
+++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
@@ -200,6 +200,8 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
 	lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR;
 	lpc_snoop->chan[channel].miscdev.name =
 		devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, channel);
+	if (!lpc_snoop->chan[channel].miscdev.name)
+		return -ENOMEM;
 	lpc_snoop->chan[channel].miscdev.fops = &snoop_fops;
 	lpc_snoop->chan[channel].miscdev.parent = dev;
 	rc = misc_register(&lpc_snoop->chan[channel].miscdev);
-- 
2.34.1

Re: [PATCH] drivers/misc: Add NULL check in aspeed_lpc_enable_snoop

Posted by Krzysztof Kozlowski 8 months, 3 weeks ago

On 31/03/2025 11:39, Henry Martin wrote:
> When devm_kasprintf() fails, it returns a NULL pointer. However, this return value is not properly checked in the function aspeed_lpc_enable_snoop.
> 
> A NULL check should be added after the devm_kasprintf() to prevent potential NULL pointer dereference error.
> 

Same comments.

> Fixes: 3772e5da44542 ("Aspeed LPC snoop output using misc chardev")
> 

There is never a blank line between tags.

> Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
> ---
>  drivers/soc/aspeed/aspeed-lpc-snoop.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> index 9ab5ba9cf1d6..376b3a910797 100644
> --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> @@ -200,6 +200,8 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
>  	lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR;
>  	lpc_snoop->chan[channel].miscdev.name =
>  		devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, channel);
> +	if (!lpc_snoop->chan[channel].miscdev.name)
> +		return -ENOMEM;

Missing cleanup.

Best regards,
Krzysztof