Re: [PATCH batadv 4/5] batman-adv: remove global hardif list

On Monday, 19 May 2025 22:46:31 CEST Matthias Schiffer wrote:
> @@ -876,6 +869,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
>         batadv_purge_outstanding_packets(bat_priv, hard_iface);
>         netdev_put(hard_iface->mesh_iface, &hard_iface->meshif_dev_tracker);
>  
> +       batadv_hardif_generation++;
>         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->mesh_iface);
>         batadv_hardif_recalc_extra_skbroom(hard_iface->mesh_iface);

I think, the following code also has to be removed from here:


	netdev_put(hard_iface->mesh_iface, &hard_iface->meshif_dev_tracker);
...
	hard_iface->mesh_iface = NULL;


And following has to be added then to the batadv_hardif_release function.

	netdev_put(hard_iface->mesh_iface, &hard_iface->meshif_dev_tracker);

Otherwise code which iterates via RCU over the netdevices list might find a 
batadv_hard_iface which is currently getting removed - but it can still find 
it and might try to access hard_iface->mesh_iface (which is NULL at that 
point).

Regards,
	Sven

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