From 20d7658b74169f86d4ac01b9185b3eadddf71f28 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 13 Jun 2026 23:50:28 +0200 Subject: [PATCH] batman-adv: dat: prevent false sharing between VLANs The local hash of DAT entries is supposed to be VLAN (VID) aware. But the adding to the hash and the search in the hash were not checking the VID information of the hash entries. The entries would therefore only be correctly separated when batadv_hash_dat() didn't select the same buckets for different VIDs. Cc: stable@kernel.org Fixes: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Sven Eckelmann --- net/batman-adv/distributed-arp-table.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index aaea155b9403..ae39ceaa2e29 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -215,10 +215,13 @@ static void batadv_dat_purge(struct work_struct *work) */ static bool batadv_compare_dat(const struct hlist_node *node, const void *data2) { - const void *data1 = container_of(node, struct batadv_dat_entry, - hash_entry); + const struct batadv_dat_entry *entry1; + const struct batadv_dat_entry *entry2; - return memcmp(data1, data2, sizeof(__be32)) == 0; + entry1 = container_of(node, struct batadv_dat_entry, hash_entry); + entry2 = data2; + + return entry1->ip == entry2->ip && entry1->vid == entry2->vid; } /** @@ -345,6 +348,9 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, if (dat_entry->ip != ip) continue; + if (dat_entry->vid != vid) + continue; + if (!kref_get_unless_zero(&dat_entry->refcount)) continue;