[B.A.T.M.A.N.] [PATCH 2/4] batman-adv: fix reference counting imbalance while sending fragment

Antonio Quartulli antonio at meshcoding.com
Thu May 15 20:50:50 CEST 2014

From: Antonio Quartulli <antonio at open-mesh.com>

In the new fragmentation code the batadv_frag_send_packet()
function obtains a reference to the primary_if, but it does
not release it upon return.

This reference imbalance prevents the primary_if (and then
the related netdevice) to be properly released on shut down.

Fix this by releasing the primary_if in batadv_frag_send_packet().

Introduced by ee75ed88879af88558818a5c6609d85f60ff0df4
("batman-adv: Fragment and send skbs larger than mtu")

Cc: Martin Hundebøll <martin at hundeboll.net>
Signed-off-by: Antonio Quartulli <antonio at open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner at neomailbox.ch>
Acked-by: Martin Hundebøll <martin at hundeboll.net>
 net/batman-adv/fragmentation.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index bcc4bea..f14e54a 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -418,12 +418,13 @@ bool batadv_frag_send_packet(struct sk_buff *skb,
 			     struct batadv_neigh_node *neigh_node)
 	struct batadv_priv *bat_priv;
-	struct batadv_hard_iface *primary_if;
+	struct batadv_hard_iface *primary_if = NULL;
 	struct batadv_frag_packet frag_header;
 	struct sk_buff *skb_fragment;
 	unsigned mtu = neigh_node->if_incoming->net_dev->mtu;
 	unsigned header_size = sizeof(frag_header);
 	unsigned max_fragment_size, max_packet_size;
+	bool ret = false;
 	/* To avoid merge and refragmentation at next-hops we never send
 	 * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE
@@ -483,7 +484,11 @@ bool batadv_frag_send_packet(struct sk_buff *skb,
 			   skb->len + ETH_HLEN);
 	batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
-	return true;
+	ret = true;
-	return false;
+	if (primary_if)
+		batadv_hardif_free_ref(primary_if);
+	return ret;

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