From: Yang Yang Date: Sat, 14 Mar 2026 07:11:27 +0000 (+0000) Subject: batman-adv: avoid OGM aggregation when skb tailroom is insufficient X-Git-Tag: v7.0-rc5~31^2~11^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0d4aef630be9d5f9c1227d07669c26c4383b5ad0;p=thirdparty%2Fkernel%2Flinux.git 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 --- 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;