If we are the only potential MLD querier but don't have an IPv6 link-local address configured on our bridge interface then we can't create a valid MLD query and in turn can't reliably receive MLD reports and can't build a complete MDB. Hence disable the new multicast active state variable then. Or reenable it if an IPv6 link-local address became available. No functional change for the fast/data path yet. Signed-off-by: Linus Lüssing --- net/bridge/br_multicast.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 2e5b5281e484..b689e62b9e74 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1112,6 +1112,7 @@ static void br_ip6_multicast_update_active(struct net_bridge_mcast *brmctx, * The multicast active state is set, per protocol family, if: * * - an IGMP/MLD querier is present + * - for own IPv6 MLD querier: an IPv6 address is configured on the bridge * * And is unset otherwise. * @@ -1206,10 +1207,12 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge_mcast *brm &ip6h->daddr, 0, &ip6h->saddr)) { kfree_skb(skb); br_opt_toggle(brmctx->br, BROPT_HAS_IPV6_ADDR, false); + br_multicast_update_active(brmctx); return NULL; } br_opt_toggle(brmctx->br, BROPT_HAS_IPV6_ADDR, true); + br_multicast_update_active(brmctx); ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest); hopopt = (u8 *)(ip6h + 1); -- 2.50.1