Commit 17a86915 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Antonio Quartulli
Browse files

batman-adv: Use kref_get for hard_iface subfunctions 



The callers of the functions using batadv_hard_iface objects already make
sure that they hold a valid reference. The subfunctions don't have
to check whether the reference counter is > 0 because this was checked by
the callers.

The kref_get function instead WARNs (with debug information) when the
reference counter would still be 0. This makes a bug in batman-adv better
visible because kref_get_unless_zero would have ignored this problem.

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarAntonio Quartulli <a@unstable.cc>
parent c3ba37a7

net/batman-adv/bat_iv_ogm.c

+3 −11
Original line number Diff line number Diff line
@@ -681,18 +681,12 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	unsigned char *skb_buff;

	unsigned int skb_size;



	if (!kref_get_unless_zero(&if_incoming->refcount))

		return;



	if (!kref_get_unless_zero(&if_outgoing->refcount))

		goto out_free_incoming;



	/* own packet should always be scheduled */

	if (!own_packet) {

		if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {

			batadv_dbg(BATADV_DBG_BATMAN, bat_priv,

				   "batman packet queue full\n");

			goto out_free_outgoing;

			return;

		}

	}
@@ -718,6 +712,8 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, 
	forw_packet_aggr->packet_len = packet_len;

	memcpy(skb_buff, packet_buff, packet_len);



	kref_get(&if_incoming->refcount);

	kref_get(&if_outgoing->refcount);

	forw_packet_aggr->own = own_packet;

	forw_packet_aggr->if_incoming = if_incoming;

	forw_packet_aggr->if_outgoing = if_outgoing;
@@ -747,10 +743,6 @@ out_free_forw_packet: 
out_nomem:

	if (!own_packet)

		atomic_inc(&bat_priv->batman_queue_left);

out_free_outgoing:

	batadv_hardif_put(if_outgoing);

out_free_incoming:

	batadv_hardif_put(if_incoming);

}



/* aggregate a new packet into the existing ogm packet */

net/batman-adv/hard-interface.c

+3 −4
Original line number Diff line number Diff line
@@ -236,8 +236,8 @@ static void batadv_primary_if_select(struct batadv_priv *bat_priv, 


	ASSERT_RTNL();



	if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount))

		new_hard_iface = NULL;

	if (new_hard_iface)

		kref_get(&new_hard_iface->refcount);



	curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);

	rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
@@ -467,8 +467,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, 
	if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)

		goto out;



	if (!kref_get_unless_zero(&hard_iface->refcount))

		goto out;

	kref_get(&hard_iface->refcount);



	soft_iface = dev_get_by_name(net, iface_name);

net/batman-adv/originator.c

+7 −23
Original line number Diff line number Diff line
@@ -374,12 +374,8 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node, 
	if (!orig_ifinfo)

		goto out;



	if (if_outgoing != BATADV_IF_DEFAULT &&

	    !kref_get_unless_zero(&if_outgoing->refcount)) {

		kfree(orig_ifinfo);

		orig_ifinfo = NULL;

		goto out;

	}

	if (if_outgoing != BATADV_IF_DEFAULT)

		kref_get(&if_outgoing->refcount);



	reset_time = jiffies - 1;

	reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
@@ -455,11 +451,8 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh, 
	if (!neigh_ifinfo)

		goto out;



	if (if_outgoing && !kref_get_unless_zero(&if_outgoing->refcount)) {

		kfree(neigh_ifinfo);

		neigh_ifinfo = NULL;

		goto out;

	}

	if (if_outgoing)

		kref_get(&if_outgoing->refcount);



	INIT_HLIST_NODE(&neigh_ifinfo->list);

	kref_init(&neigh_ifinfo->refcount);
@@ -532,15 +525,11 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, 
	if (hardif_neigh)

		goto out;



	if (!kref_get_unless_zero(&hard_iface->refcount))

		goto out;



	hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC);

	if (!hardif_neigh) {

		batadv_hardif_put(hard_iface);

	if (!hardif_neigh)

		goto out;

	}



	kref_get(&hard_iface->refcount);

	INIT_HLIST_NODE(&hardif_neigh->list);

	ether_addr_copy(hardif_neigh->addr, neigh_addr);

	hardif_neigh->if_incoming = hard_iface;
@@ -643,16 +632,11 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, 
	if (!neigh_node)

		goto out;



	if (!kref_get_unless_zero(&hard_iface->refcount)) {

		kfree(neigh_node);

		neigh_node = NULL;

		goto out;

	}



	INIT_HLIST_NODE(&neigh_node->list);

	INIT_HLIST_HEAD(&neigh_node->ifinfo_list);

	spin_lock_init(&neigh_node->ifinfo_lock);



	kref_get(&hard_iface->refcount);

	ether_addr_copy(neigh_node->addr, neigh_addr);

	neigh_node->if_incoming = hard_iface;

	neigh_node->orig_node = orig_node;

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