Author: marek Date: 2010-08-29 02:02:14 +0200 (Sun, 29 Aug 2010) New Revision: 1780

Modified: trunk/batman-adv/hard-interface.c Log: batman-adv: Don't rely on NF_HOOKs return value

If a hook returns NF_STOLEN, neither batman_skb_recv nor batman_skb_recv_finish free the skb due to the asynchronous netfilter handling in the kernel. Therefore not batman_skb_recv but the ok function batman_skb_recv_finish should do the freeing when a recv subfunction returns NET_RX_DROP instead.

Reported-by: Vasiliy Kulikov segooon@gmail.com Signed-off-by: Linus L?\195?\188ssing linus.luessing@web.de

Modified: trunk/batman-adv/hard-interface.c =================================================================== --- trunk/batman-adv/hard-interface.c 2010-08-29 00:02:13 UTC (rev 1779) +++ trunk/batman-adv/hard-interface.c 2010-08-29 00:02:14 UTC (rev 1780) @@ -497,56 +497,27 @@

static int batman_skb_recv_finish(struct sk_buff *skb) { - return NF_ACCEPT; -} - -/* receive a packet with the batman ethertype coming on a hard - * interface */ -int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, - struct packet_type *ptype, struct net_device *orig_dev) -{ - struct bat_priv *bat_priv; struct batman_packet *batman_packet; struct batman_if *batman_if; + struct bat_priv *bat_priv; int ret;

- batman_if = container_of(ptype, struct batman_if, batman_adv_ptype); - skb = skb_share_check(skb, GFP_ATOMIC); - - /* skb was released by skb_share_check() */ - if (!skb) - goto err_out; - - /* if netfilter/ebtables wants to block incoming batman - * packets then give them a chance to do so here */ - ret = NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, dev, NULL, - batman_skb_recv_finish); - if (ret != 1) - goto err_out; - - /* packet should hold at least type and version */ - if (unlikely(!pskb_may_pull(skb, 2))) + batman_if = get_batman_if_by_netdev(skb->dev); + if (!batman_if) goto err_free;

- /* expect a valid ethernet header here. */ - if (unlikely(skb->mac_len != sizeof(struct ethhdr) - || !skb_mac_header(skb))) + if (!batman_if->soft_iface) goto err_free;

- if (!batman_if->soft_iface) + /* discard frames on not active interfaces */ + if (batman_if->if_status != IF_ACTIVE) goto err_free;

bat_priv = netdev_priv(batman_if->soft_iface); - if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE) goto err_free;

- /* discard frames on not active interfaces */ - if (batman_if->if_status != IF_ACTIVE) - goto err_free; - batman_packet = (struct batman_packet *)skb->data; - if (batman_packet->version != COMPAT_VERSION) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: incompatible batman version (%i)\n", @@ -592,18 +563,42 @@ }

if (ret == NET_RX_DROP) - kfree_skb(skb); + goto err_free;

- /* return NET_RX_SUCCESS in any case as we - * most probably dropped the packet for - * routing-logical reasons. */ + return 0;

- return NET_RX_SUCCESS; +err_free: + kfree_skb(skb); + return 0; +}

+/* receive a packet with the batman ethertype coming on a hard + * interface */ +int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *ptype, struct net_device *orig_dev) +{ + skb = skb_share_check(skb, GFP_ATOMIC); + + /* skb was released by skb_share_check() */ + if (!skb) + return 0; + + /* packet should hold at least type and version */ + if (unlikely(!pskb_may_pull(skb, 2))) + goto err_free; + + /* expect a valid ethernet header here. */ + if (unlikely(skb->mac_len != sizeof(struct ethhdr) || + !skb_mac_header(skb))) + goto err_free; + + /* if netfilter/ebtables wants to block incoming batman + * packets then give them a chance to do so here */ + return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, dev, + NULL, batman_skb_recv_finish); err_free: kfree_skb(skb); -err_out: - return NET_RX_DROP; + return 0; }

struct notifier_block hard_if_notifier = {