[PATCH 3.16 241/366] RDMA/iwpm: fix memory leak on map_info

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

commit f96416cea7bce9afe619c15e87fced70f93f9098 upstream.

In the cases where iwpm_hash_bucket is NULL and where function
get_mapinfo_hash_bucket returns NULL then the map_info is never added
to hash_bucket_head and hence there is a leak of map_info. Fix this
by nullifying hash_bucket_head and if that is null we know that
that map_info was not added to hash_bucket_head and hence map_info
should be free'd.

Detected by CoverityScan, CID#1222481 ("Resource Leak")

Fixes: 30dc5e63d6a5 ("RDMA/core: Add support for iWARP Port Mapper user space service")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/infiniband/core/iwpm_util.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/core/iwpm_util.c
+++ b/drivers/infiniband/core/iwpm_util.c
@@ -96,7 +96,7 @@ int iwpm_create_mapinfo(struct sockaddr_
 			struct sockaddr_storage *mapped_sockaddr,
 			u8 nl_client)
 {
-	struct hlist_head *hash_bucket_head;
+	struct hlist_head *hash_bucket_head = NULL;
 	struct iwpm_mapping_info *map_info;
 	unsigned long flags;
 
@@ -121,6 +121,9 @@ int iwpm_create_mapinfo(struct sockaddr_
 		hlist_add_head(&map_info->hlist_node, hash_bucket_head);
 	}
 	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
+
+	if (!hash_bucket_head)
+		kfree(map_info);
 	return 0;
 }
 EXPORT_SYMBOL(iwpm_create_mapinfo);