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[6/9] batman-adv: Use kref_get for batadv_nc_get_nc_node

Message ID 1457190564-11419-6-git-send-email-sven@narfation.org
State Accepted, archived
Commit e0fbb37fe0b0ae615f555346150174de6277df9c
Delegated to: Marek Lindner
Headers show

Commit Message

Sven Eckelmann March 5, 2016, 3:09 p.m. UTC
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(-)

Comments

Marek Lindner April 11, 2016, 10:24 a.m. UTC | #1
On Saturday, March 05, 2016 16:09:21 Sven Eckelmann wrote:
> 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(-)

Applied in revision e0fbb37.

Thanks,
Marek
diff mbox

Patch

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;
 }
 
 /**