Merge tag 'batadv-net-pullrequest-20260408' of https://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are two batman-adv bugfixes:

 - reject oversized global TT response buffers, by Ruide Cao

 - hold claim backbone gateways by reference, by Haoze Xie

* tag 'batadv-net-pullrequest-20260408' of https://git.open-mesh.org/linux-merge:
  batman-adv: hold claim backbone gateways by reference
  batman-adv: reject oversized global TT response buffers
====================

Link: https://patch.msgid.link/20260408110255.976389-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 25 insertions, 11 deletions

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 49ae92b9a1526..51fe028b90881 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -2130,6 +2130,7 @@ batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid,
 			    struct batadv_bla_claim *claim)
 {
 	const u8 *primary_addr = primary_if->net_dev->dev_addr;
+	struct batadv_bla_backbone_gw *backbone_gw;
 	u16 backbone_crc;
 	bool is_own;
 	void *hdr;
@@ -2145,32 +2146,35 @@ batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid,
 
 	genl_dump_check_consistent(cb, hdr);
 
-	is_own = batadv_compare_eth(claim->backbone_gw->orig,
-				    primary_addr);
+	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
+
+	is_own = batadv_compare_eth(backbone_gw->orig, primary_addr);
 
-	spin_lock_bh(&claim->backbone_gw->crc_lock);
-	backbone_crc = claim->backbone_gw->crc;
-	spin_unlock_bh(&claim->backbone_gw->crc_lock);
+	spin_lock_bh(&backbone_gw->crc_lock);
+	backbone_crc = backbone_gw->crc;
+	spin_unlock_bh(&backbone_gw->crc_lock);
 
 	if (is_own)
 		if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) {
 			genlmsg_cancel(msg, hdr);
-			goto out;
+			goto put_backbone_gw;
 		}
 
 	if (nla_put(msg, BATADV_ATTR_BLA_ADDRESS, ETH_ALEN, claim->addr) ||
 	    nla_put_u16(msg, BATADV_ATTR_BLA_VID, claim->vid) ||
 	    nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN,
-		    claim->backbone_gw->orig) ||
+		    backbone_gw->orig) ||
 	    nla_put_u16(msg, BATADV_ATTR_BLA_CRC,
 			backbone_crc)) {
 		genlmsg_cancel(msg, hdr);
-		goto out;
+		goto put_backbone_gw;
 	}
 
 	genlmsg_end(msg, hdr);
 	ret = 0;
 
+put_backbone_gw:
+	batadv_backbone_gw_put(backbone_gw);
 out:
 	return ret;
 }
@@ -2448,6 +2452,7 @@ out:
 bool batadv_bla_check_claim(struct batadv_priv *bat_priv,
 			    u8 *addr, unsigned short vid)
 {
+	struct batadv_bla_backbone_gw *backbone_gw;
 	struct batadv_bla_claim search_claim;
 	struct batadv_bla_claim *claim = NULL;
 	struct batadv_hard_iface *primary_if = NULL;
@@ -2470,9 +2475,13 @@ bool batadv_bla_check_claim(struct batadv_priv *bat_priv,
 	 * return false.
 	 */
 	if (claim) {
-		if (!batadv_compare_eth(claim->backbone_gw->orig,
+		backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
+
+		if (!batadv_compare_eth(backbone_gw->orig,
 					primary_if->net_dev->dev_addr))
 			ret = false;
+
+		batadv_backbone_gw_put(backbone_gw);
 		batadv_claim_put(claim);
 	}
 
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 6e95e883c2bf0..05cddcf994f65 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -798,8 +798,8 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 {
 	u16 num_vlan = 0;
 	u16 num_entries = 0;
-	u16 change_offset;
-	u16 tvlv_len;
+	u16 tvlv_len = 0;
+	unsigned int change_offset;
 	struct batadv_tvlv_tt_vlan_data *tt_vlan;
 	struct batadv_orig_node_vlan *vlan;
 	u8 *tt_change_ptr;
@@ -816,6 +816,11 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node,
 	if (*tt_len < 0)
 		*tt_len = batadv_tt_len(num_entries);
 
+	if (change_offset > U16_MAX || *tt_len > U16_MAX - change_offset) {
+		*tt_len = 0;
+		goto out;
+	}
+
 	tvlv_len = *tt_len;
 	tvlv_len += change_offset;