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

[Christian Marangi]

On Wed, Jun 14, 2023 at 04:55:10PM +0200, Simon Horman wrote:
> 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 <Jose.Abreu@xxxxxxxxxxxx>
> > Fixes: ba39b344e924 ("net: ethernet: stmicro: stmmac: generate stmmac dma conf before open")
> > Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx
> > ---
> >  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.
>

Yes, they are. Handling in the caller would require some additional
delta to this and some duplicated code but if preferred I can implement
it. I can provide a v2 shortly if it's ok and you prefer this
implementation.

> >  	return ret;
> >  }
> >  
> > -- 
> > 2.40.1
> > 
> > 

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