From: Antonio Quartulli antonio@open-mesh.com
A pointer to the orig_node representing a bat-gateway is stored in the gw_node->orig_node member, but the refcount for such orig_node is never increased. This leads to memory faults when gw_node->orig_node is accessed and the originator has already been freed.
Fix this by increasing the refcount on gw_node creation and decreasing it on gw_node free.
Signed-off-by: Antonio Quartulli antonio@open-mesh.com ---
Change since v1: - properly release orig_node in case of gw_node allocation failure
gateway_client.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/gateway_client.c b/gateway_client.c index d7fafc1..d5a40ab 100644 --- a/gateway_client.c +++ b/gateway_client.c @@ -42,8 +42,10 @@
static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node) { - if (atomic_dec_and_test(&gw_node->refcount)) + if (atomic_dec_and_test(&gw_node->refcount)) { + batadv_orig_node_free_ref(gw_node->orig_node); kfree_rcu(gw_node, rcu); + } }
static struct batadv_gw_node * @@ -406,9 +408,14 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv, if (gateway->bandwidth_down == 0) return;
+ if (!atomic_inc_not_zero(&orig_node->refcount)) + return; + gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC); - if (!gw_node) + if (!gw_node) { + batadv_orig_node_free_ref(orig_node); return; + }
INIT_HLIST_NODE(&gw_node->list); gw_node->orig_node = orig_node;