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From: Sven Eckelmann <sven@narfation.org>
Date: Sun, 26 Jul 2015 02:41:58 +0200
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Subject: Re: [B.A.T.M.A.N.] Missing list checks for *list_add*
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On Friday 26 June 2015 16:45:01 Sven Eckelmann wrote:
> Hi,
> 
> Simon debugged the refcnt problem and submitted some patches to fix them. I
> had a brief look and noticed that there are possible more problems similar
> to the *list_del* ones - just with *list_add*. Basically some functions use
> some kind of get function, notice that the element does not exist and then
> create a new one to add to the list. Only the "list_add" is protected. The
> result may be that an element in twice in a list when only a single
> occurrence is allowed.
> 
> The problem I saw is batadv_gw_node_update. It first calls
> batadv_gw_node_get to check if an object with this value already exists and
> then uses batadv_gw_node_add to add a node (which may already be added
> between these two calls). So it has to be made sure that nothing modifies
> the list between these two calls).
> 
> Similar looking functions are for example:
> 
>  * batadv_tvlv_handler_register
>  * batadv_nc_get_nc_node
>  * batadv_softif_create_vlan
>  * batadv_tt_global_orig_entry_add

*push*
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