Subject: Re: [net PATCH] net: ethernet: stmicro: stmmac: fix possible memory leak in __stmmac_open

From: Simon Horman <[email-masked]>
Date: Wed, 14 Jun 2023 16:55:10 +0200

On Wed, Jun 14, 2023 at 09:32:41AM +0200, Christian Marangi wrote:
> Fix a possible memory leak in __stmmac_open when stmmac_init_phy fails.
> It's also needed to free everything allocated by stmmac_setup_dma_desc
> and not just the dma_conf struct.
> 
> Correctly call free_dma_desc_resources on the new dma_conf passed to
> __stmmac_open on error.
> 
> Reported-by: Jose Abreu <[email-masked]>
> Fixes: ba39b344e924 ("net: ethernet: stmicro: stmmac: generate stmmac dma conf before open")
> Signed-off-by: Christian Marangi <[email-masked]>
> Cc: [email-masked]
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index fa07b0d50b46..0966ab86fde2 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3877,10 +3877,10 @@ static int __stmmac_open(struct net_device *dev,
>  
>  	stmmac_hw_teardown(dev);
>  init_error:
> -	free_dma_desc_resources(priv, &priv->dma_conf);
>  	phylink_disconnect_phy(priv->phylink);
>  init_phy_error:
>  	pm_runtime_put(priv->device);
> +	free_dma_desc_resources(priv, dma_conf);

Hi Christian,

Are these resources allocated by the caller?
If so, perhaps it would be clearer if a symmetric approach
was taken and the caller handled freeing them on error.

>  	return ret;
>  }
> -- 
> 2.40.1