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

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

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


> +
> +		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