Re: [PATCH v2] net: mv643xx_eth: fix an OF node reference leak

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

On Mon, Dec 16, 2024 at 01:22:47PM +0900, Joe Hattori wrote:
> Current implementation of mv643xx_eth_shared_of_add_port() calls
> of_parse_phandle(), but does not release the refcount on error. Call
> of_node_put() in the error path and in mv643xx_eth_shared_of_remove().
> 
> This bug was found by an experimental static analysis tool that I am
> developing.
> 
> Fixes: 76723bca2802 ("net: mv643xx_eth: add DT parsing support")
> Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
> ---
> Changes in v2:
> - Insert a null check before accessing the platform data.
> ---
>  drivers/net/ethernet/marvell/mv643xx_eth.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
> index a06048719e84..917ff7bd43d4 100644
> --- a/drivers/net/ethernet/marvell/mv643xx_eth.c
> +++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
> @@ -2705,8 +2705,12 @@ static struct platform_device *port_platdev[3];
>  static void mv643xx_eth_shared_of_remove(void)
>  {
>  	int n;
> +	struct mv643xx_eth_platform_data *pd;
>  
>  	for (n = 0; n < 3; n++) {
> +		pd = dev_get_platdata(&port_platdev[n]->dev);
> +		if (pd)
> +			of_node_put(pd->phy_node);
>  		platform_device_del(port_platdev[n]);
>  		port_platdev[n] = NULL;
>  	}
> @@ -2769,8 +2773,10 @@ static int mv643xx_eth_shared_of_add_port(struct platform_device *pdev,
>  	}
>  
>  	ppdev = platform_device_alloc(MV643XX_ETH_NAME, dev_num);
> -	if (!ppdev)
> -		return -ENOMEM;
> +	if (!ppdev) {
> +		ret = -ENOMEM;
> +		goto put_err;
> +	}
>  	ppdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
>  	ppdev->dev.of_node = pnp;
>  
> @@ -2792,6 +2798,8 @@ static int mv643xx_eth_shared_of_add_port(struct platform_device *pdev,
>  
>  port_err:
>  	platform_device_put(ppdev);
> +put_err:
> +	of_node_put(ppd.phy_node);
>  	return ret;
>  }
>
Looks good
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>

Thanks
> -- 
> 2.34.1