From: Antonio Quartulli Date: Thu, 1 May 2014 23:35:13 +0000 (+0200) Subject: batman-adv: increase orig refcount when storing ref in gw_node X-Git-Tag: v4.9.8~6360^2~21^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=377fe0f968b30a1a714fab53a908061914f30e26;p=platform%2Fkernel%2Flinux-rpi3.git batman-adv: increase orig refcount when storing ref in gw_node 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 Signed-off-by: Marek Lindner --- diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index c835e13..90cff58 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/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;