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From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: [B.A.T.M.A.N.] [PATCH 6/9] batman-adv: Use kref_get for batadv_nc_get_nc_node
Date: Sat,  5 Mar 2016 16:09:21 +0100	[thread overview]
Message-ID: <1457190564-11419-6-git-send-email-sven@narfation.org> (raw)
In-Reply-To: <1457190564-11419-1-git-send-email-sven@narfation.org>

batadv_nc_get_nc_node requires that the caller already has a valid
reference for orig_neigh_node. It is therefore not possible that it has an
reference counter of 0 and was still given to this function

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: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/network-coding.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 32f9fa1..4f7a558 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -856,8 +856,7 @@ static struct batadv_nc_node
 	if (!nc_node)
 		return NULL;
 
-	if (!kref_get_unless_zero(&orig_neigh_node->refcount))
-		goto free;
+	kref_get(&orig_neigh_node->refcount);
 
 	/* Initialize nc_node */
 	INIT_LIST_HEAD(&nc_node->list);
@@ -884,10 +883,6 @@ static struct batadv_nc_node
 	spin_unlock_bh(lock);
 
 	return nc_node;
-
-free:
-	kfree(nc_node);
-	return NULL;
 }
 
 /**
-- 
2.7.0


  parent reply	other threads:[~2016-03-05 15:09 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-05 15:09 [B.A.T.M.A.N.] [PATCH 1/9] batman-adv: Check hard_iface refcnt before calling function Sven Eckelmann
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 2/9] batman-adv: Check hard_iface refcnt when receiving skb Sven Eckelmann
2016-03-28 14:27   ` Marek Lindner
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 3/9] batman-adv: Increase hard_iface refcnt for ptype Sven Eckelmann
2016-03-31  8:58   ` Marek Lindner
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 4/9] batman-adv: Use kref_get for hard_iface subfunctions Sven Eckelmann
2016-04-11 10:13   ` Marek Lindner
2016-04-11 10:55     ` Sven Eckelmann
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 5/9] batman-adv: Use kref_get for batadv_tvlv_container_get Sven Eckelmann
2016-04-11 10:18   ` Marek Lindner
2016-03-05 15:09 ` Sven Eckelmann [this message]
2016-04-11 10:24   ` [B.A.T.M.A.N.] [PATCH 6/9] batman-adv: Use kref_get for batadv_nc_get_nc_node Marek Lindner
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 7/9] batman-adv: Use kref_get for batadv_gw_select Sven Eckelmann
2016-04-11 10:25   ` Marek Lindner
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 8/9] batman-adv: Use kref_get for batadv_gw_node_add Sven Eckelmann
2016-04-11 10:29   ` Marek Lindner
2016-03-05 15:09 ` [B.A.T.M.A.N.] [PATCH 9/9] batman-adv: Use kref_get for _batadv_update_route Sven Eckelmann
2016-03-05 18:05   ` [B.A.T.M.A.N.] [PATCH v2 " Sven Eckelmann
2016-04-11 10:36     ` Marek Lindner
2016-03-06  0:08 ` [B.A.T.M.A.N.] [PATCH 1/9] batman-adv: Check hard_iface refcnt before calling function Andrew Lunn
2016-03-06  8:55   ` Sven Eckelmann
2016-03-06 14:10     ` Andrew Lunn
2016-03-28 14:19 ` Marek Lindner

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