Re: [PATCH net v3] RDMA/core: Reject unregistering netdevs in ib_get_eth_speed

[Jason Gunthorpe]

On Mon, Aug 10, 2026 at 03:31:20PM +0200, Krystian Kaniewski wrote:

> @@ -2049,7 +2050,15 @@ int ib_get_eth_speed(struct ib_device *dev, u32 port_num, u16 *speed, u8 *width)
>  		return -ENODEV;
>  
>  	rtnl_lock();
> +	if (READ_ONCE(netdev->reg_state) != NETREG_REGISTERED) {
> +		dev_put(netdev);
> +		rtnl_unlock();
> +		return -ENODEV;
> +	}
> +
>  	rc = __ethtool_get_link_ksettings(netdev, &lksettings);
> +	if (rc)
> +		strscpy(name, netdev->name, sizeof(name));
>  	rtnl_unlock();
>  
>  	dev_put(netdev);
> @@ -2060,7 +2069,7 @@ int ib_get_eth_speed(struct ib_device *dev, u32 port_num, u16 *speed, u8 *width)
>  		netdev_speed = SPEED_1000;
>  		if (rc)
>  			pr_warn("%s speed is unknown, defaulting to %u\n",
> -				netdev->name, netdev_speed);
> +				name, netdev_speed);
>  	}

I would probably just put this block inside the rtnl lock and not copy
the netdev->name

Jason