batadv_tp_recv_ack() is only valid for tp_vars in the BATADV_TP_SENDER role. When called with a BATADV_TP_RECEIVER role, it proceeds to read sender-only members that were never initialized, leading to undefined behavior.
This can be triggered when a node that is currently acting as a receiver in an ongoing tp_meter session receives a malicious ACK packet. Guard against this by checking tp_vars->role immediately after the lookup and bailing out if it is not BATADV_TP_SENDER, before any of those members are accessed. Cc: [email protected] Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation") 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/tp_meter.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 759ae923..84af22fa 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -664,6 +664,9 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, if (unlikely(!tp_vars)) return; + if (unlikely(tp_vars->role != BATADV_TP_SENDER)) + goto out; + if (unlikely(atomic_read(&tp_vars->sending) == 0)) goto out; -- 2.47.3
