When a batadv_hard_iface is disabled, its mesh_iface pointer is set to NULL. However, batadv_v_ogm_send_meshif() may still dispatch OGMs via batadv_v_ogm_queue_on_if() for interfaces that have since lost their mesh_iface association. This results in a NULL pointer dereference when batadv_v_ogm_queue_on_if() unconditionally calls netdev_priv() on the now NULL hard_iface->mesh_iface to retrieve the batadv_priv.
It is necessary to ensure that the batadv_v_ogm_queue_on_if() checks that it is using the same mesh_iface for which batadv_v_ogm_send_meshif() was called. Cc: [email protected] Fixes: 0da0035942d4 ("batman-adv: OGMv2 - add basic infrastructure") Reported-by: Yuan Tan <[email protected]> Reported-by: Yifan Wu <[email protected]> Reported-by: Juefei Pu <[email protected]> Reported-by: Xin Liu <[email protected]> Signed-off-by: Sven Eckelmann <[email protected]> --- net/batman-adv/bat_v_ogm.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index e3870492..0643a723 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -113,14 +113,14 @@ static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) /** * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface + * @bat_priv: the bat priv with all the mesh interface information * @skb: the OGM to send * @hard_iface: the interface to use to send the OGM */ -static void batadv_v_ogm_send_to_if(struct sk_buff *skb, +static void batadv_v_ogm_send_to_if(struct batadv_priv *bat_priv, + struct sk_buff *skb, struct batadv_hard_iface *hard_iface) { - struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface); - if (hard_iface->if_status != BATADV_IF_ACTIVE) { kfree_skb(skb); return; @@ -187,6 +187,7 @@ static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) /** * batadv_v_ogm_aggr_send() - flush & send aggregation queue + * @bat_priv: the bat priv with all the mesh interface information * @hard_iface: the interface with the aggregation queue to flush * * Aggregates all OGMv2 packets currently in the aggregation queue into a @@ -196,7 +197,8 @@ static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) * * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. */ -static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) +static void batadv_v_ogm_aggr_send(struct batadv_priv *bat_priv, + struct batadv_hard_iface *hard_iface) { unsigned int aggr_len = hard_iface->bat_v.aggr_len; struct sk_buff *skb_aggr; @@ -226,27 +228,32 @@ static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) consume_skb(skb); } - batadv_v_ogm_send_to_if(skb_aggr, hard_iface); + batadv_v_ogm_send_to_if(bat_priv, skb_aggr, hard_iface); } /** * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface + * @bat_priv: the bat priv with all the mesh interface information * @skb: the OGM to queue * @hard_iface: the interface to queue the OGM on */ -static void batadv_v_ogm_queue_on_if(struct sk_buff *skb, +static void batadv_v_ogm_queue_on_if(struct batadv_priv *bat_priv, + struct sk_buff *skb, struct batadv_hard_iface *hard_iface) { - struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface); + if (hard_iface->mesh_iface != bat_priv->mesh_iface) { + kfree_skb(skb); + return; + } if (!atomic_read(&bat_priv->aggregated_ogms)) { - batadv_v_ogm_send_to_if(skb, hard_iface); + batadv_v_ogm_send_to_if(bat_priv, skb, hard_iface); return; } spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); if (!batadv_v_ogm_queue_left(skb, hard_iface)) - batadv_v_ogm_aggr_send(hard_iface); + batadv_v_ogm_aggr_send(bat_priv, hard_iface); hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); @@ -343,7 +350,7 @@ static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv) break; } - batadv_v_ogm_queue_on_if(skb_tmp, hard_iface); + batadv_v_ogm_queue_on_if(bat_priv, skb_tmp, hard_iface); batadv_hardif_put(hard_iface); } rcu_read_unlock(); @@ -383,12 +390,20 @@ void batadv_v_ogm_aggr_work(struct work_struct *work) { struct batadv_hard_iface_bat_v *batv; struct batadv_hard_iface *hard_iface; + struct batadv_priv *bat_priv; + struct net_device *meshif; batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work); hard_iface = container_of(batv, struct batadv_hard_iface, bat_v); + meshif = hard_iface->mesh_iface; + + if (!meshif) + return; + + bat_priv = netdev_priv(meshif); spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); - batadv_v_ogm_aggr_send(hard_iface); + batadv_v_ogm_aggr_send(bat_priv, hard_iface); spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); batadv_v_ogm_start_queue_timer(hard_iface); @@ -578,7 +593,7 @@ static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), ogm_forward->ttl, if_incoming->net_dev->name); - batadv_v_ogm_queue_on_if(skb, if_outgoing); + batadv_v_ogm_queue_on_if(bat_priv, skb, if_outgoing); out: batadv_orig_ifinfo_put(orig_ifinfo); -- 2.47.3
