Re: [B.A.T.M.A.N.] [PATCH-maint] batman-adv: fix potential orig_node reference leak

[Antonio Quartulli <antonio@meshcoding.com>]

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On 08/02/14 16:45, Simon Wunderlich wrote:
> Since batadv_orig_node_new() sets the refcount to two, assuming that
> the calling function will use a reference for putting the orig_node into
> a hash or similar, both references must be freed if initialization of
> the orig_node fails. Otherwise that object may be leaked in that error
> case.
> 
> Reported-by: Antonio Quartulli <antonio@meshcoding.com>
> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
> ---
>  bat_iv_ogm.c |    2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/bat_iv_ogm.c b/bat_iv_ogm.c
> index 6f4fcdc..6000337 100644
> --- a/bat_iv_ogm.c
> +++ b/bat_iv_ogm.c
> @@ -256,6 +256,8 @@ batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const uint8_t *addr)
>  free_bcast_own:
>  	kfree(orig_node->bat_iv.bcast_own);
>  free_orig_node:
> +	/* free twice, as batadv_orig_node_new set refcount to 2 */
> +	batadv_orig_node_free_ref(orig_node);
>  	batadv_orig_node_free_ref(orig_node);

Coudln't we just invoke kfree(orig_node) here ? I think that if we hit
this point it is because the node has not added to the hash and
therefore it i snot used in any other context. This way we avoid the
double free_ref() and we don't trgger the whole RCU mechanism.

Or am I missing something?

Cheers,

-- 
Antonio Quartulli


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