[B.A.T.M.A.N.] [PATCH maint] batman-adv: avoid double free when orig_node initialization fails

[Antonio Quartulli <antonio@meshcoding.com>]

In the failure path of the orig_node initialization routine
a double free is hit because orig_node->bat_iv.bcast_own is
not set to NULL after being free'd.

Fix it by setting bcast_own to NULL after having free'd it.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
---
 bat_iv_ogm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/bat_iv_ogm.c b/bat_iv_ogm.c
index c07e59f..cb4c18a 100644
--- a/bat_iv_ogm.c
+++ b/bat_iv_ogm.c
@@ -255,6 +255,8 @@ batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const uint8_t *addr)
 
 free_bcast_own:
 	kfree(orig_node->bat_iv.bcast_own);
+	/* make it NULL to avoid second free in batadv_iv_ogm_orig_free() */
+	orig_node->bat_iv.bcast_own = NULL;
 free_orig_node:
 	/* free twice, as batadv_orig_node_new sets refcount to 2 */
 	batadv_orig_node_free_ref(orig_node);
-- 
1.8.5.3