Re: [PATCH v2 1/4] net: airoha: Fix an error handling path in airoha_alloc_gdm_port()

[Lorenzo Bianconi <lorenzo@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 2934 bytes --]

> Le 08/05/2025 à 17:31, Lorenzo Bianconi a écrit :
> > > If register_netdev() fails, the error handling path of the probe will not
> > > free the memory allocated by the previous airoha_metadata_dst_alloc() call
> > > because port->dev->reg_state will not be NETREG_REGISTERED.
> > > 
> > > So, an explicit airoha_metadata_dst_free() call is needed in this case to
> > > avoid a memory leak.
> > > 
> > > Fixes: af3cf757d5c9 ("net: airoha: Move DSA tag in DMA descriptor")
> > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > > ---
> > > Changes in v2:
> > >    - New patch
> > > 
> > > Compile tested only.
> > > ---
> > >   drivers/net/ethernet/airoha/airoha_eth.c | 10 +++++++++-
> > >   1 file changed, 9 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> > > index 16c7896f931f..af8c4015938c 100644
> > > --- a/drivers/net/ethernet/airoha/airoha_eth.c
> > > +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> > > @@ -2873,7 +2873,15 @@ static int airoha_alloc_gdm_port(struct airoha_eth *eth,
> > >   	if (err)
> > >   		return err;
> > > -	return register_netdev(dev);
> > > +	err = register_netdev(dev);
> > > +	if (err)
> > > +		goto free_metadata_dst;
> > > +
> > > +	return 0;
> > > +
> > > +free_metadata_dst:
> > > +	airoha_metadata_dst_free(port);
> > > +	return err;
> > >   }
> > >   static int airoha_probe(struct platform_device *pdev)
> > > -- 
> > > 2.49.0
> > > 
> > 
> > I have not tested it but I think the right fix here would be something like:
> > 
> > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> > index b1ca8322d4eb..33f8926bba25 100644
> > --- a/drivers/net/ethernet/airoha/airoha_eth.c
> > +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> > @@ -2996,10 +2996,12 @@ static int airoha_probe(struct platform_device *pdev)
> >   	for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
> >   		struct airoha_gdm_port *port = eth->ports[i];
> > -		if (port && port->dev->reg_state == NETREG_REGISTERED) {
> > +		if (!port)
> > +			continue;
> 
> I think it works.
> 
> We can still have port non NULL and airoha_metadata_dst_alloc() which fails,
> but airoha_metadata_dst_free() seems to handle it correctly.
> 
> CJ

Actually, in order to be consistent with the rest of the code where a
routine undoes changes in case of an internal failure, I would prefer your
approach. Can you please post your solution in the next iteration? Thanks.

Regards,
Lorenzo

> 
> 
> > +
> > +		if (port->dev->reg_state == NETREG_REGISTERED)
> >   			unregister_netdev(port->dev);
> > -			airoha_metadata_dst_free(port);
> > -		}
> > +		airoha_metadata_dst_free(port);
> >   	}
> >   	free_netdev(eth->napi_dev);
> >   	platform_set_drvdata(pdev, NULL);
> > 
> > Regards,
> > Lorenzo
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]