From 0d4aef630be9d5f9c1227d07669c26c4383b5ad0 Mon Sep 17 00:00:00 2001 From: Yang Yang Date: Sat, 14 Mar 2026 07:11:27 +0000 Subject: [PATCH] batman-adv: avoid OGM aggregation when skb tailroom is insufficient When OGM aggregation state is toggled at runtime, an existing forwarded packet may have been allocated with only packet_len bytes, while a later packet can still be selected for aggregation. Appending in this case can hit skb_put overflow conditions. Reject aggregation when the target skb tailroom cannot accommodate the new packet. The caller then falls back to creating a new forward packet instead of appending. Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Cc: stable@vger.kernel.org Reported-by: Yifan Wu Reported-by: Juefei Pu Signed-off-by: Yuan Tan Signed-off-by: Xin Liu Signed-off-by: Ao Zhou Signed-off-by: Yang Yang Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/bat_iv_ogm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index b75c2228e69a..f28e9cbf8ad5 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -473,6 +473,9 @@ batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet, if (aggregated_bytes > max_bytes) return false; + if (skb_tailroom(forw_packet->skb) < packet_len) + return false; + if (packet_num >= BATADV_MAX_AGGREGATION_PACKETS) return false;