Re: [PATCH net] net: macb: fix NULL pointer dereference on unbind with fixed-link

[Théo Lebrun]

Hi Nicolai,

On Thu Sep 3, 2026 at 9:23 AM CEST, Nicolai Buchwitz wrote:
> On 2.9.2026 12:28, Vineeth Karumanchi wrote:
>> @@ -5971,8 +5971,10 @@ static int macb_probe(struct platform_device 
>> *pdev)
>>  	macb_free_tieoff(bp);
>> 
>>  err_out_unregister_mdio:
>> -	mdiobus_unregister(bp->mii_bus);
>> -	mdiobus_free(bp->mii_bus);
>> +	if (bp->mii_bus) {
>> +		mdiobus_unregister(bp->mii_bus);
>> +		mdiobus_free(bp->mii_bus);
>> +	}
>> 
>>  err_out_phy_exit:
>>  	phy_exit(bp->phy);
>> @@ -6001,8 +6003,10 @@ static void macb_remove(struct platform_device 
>> *pdev)
>>  		unregister_netdev(netdev);
>>  		macb_free_tieoff(bp);
>>  		phy_exit(bp->phy);
>> -		mdiobus_unregister(bp->mii_bus);
>> -		mdiobus_free(bp->mii_bus);
>> +		if (bp->mii_bus) {
>> +			mdiobus_unregister(bp->mii_bus);
>> +			mdiobus_free(bp->mii_bus);
>> +		}
>
> nit: replica of the code from above, but also not really worth a helper?

Agreed that the helper is overblown!

Thanks,

--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com