netdev - [PATCH net-next 16/16] net: bridge: mcast: when forwarding handle filter mode and blocked flag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 Sep 2020 13:55:26 +0300
From:   Nikolay Aleksandrov <razor@...ckwall.org>
To:     netdev@...r.kernel.org
Cc:     roopa@...dia.com, davem@...emloft.net,
        bridge@...ts.linux-foundation.org,
        Nikolay Aleksandrov <nikolay@...dia.com>
Subject: [PATCH net-next 16/16] net: bridge: mcast: when forwarding handle filter mode and blocked flag

From: Nikolay Aleksandrov <nikolay@...dia.com>

We need to avoid forwarding to ports in MCAST_INCLUDE filter mode when the
mdst entry is a *,G or when the port has the blocked flag.

Signed-off-by: Nikolay Aleksandrov <nikolay@...dia.com>
---
 net/bridge/br_forward.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 4d12999e4576..e28ffadd1371 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -274,10 +274,19 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *prev = NULL;
 	struct net_bridge_port_group *p;
+	bool allow_mode_include = true;
 	struct hlist_node *rp;
 
 	rp = rcu_dereference(hlist_first_rcu(&br->router_list));
-	p = mdst ? rcu_dereference(mdst->ports) : NULL;
+	if (mdst) {
+		p = rcu_dereference(mdst->ports);
+		if (br_multicast_should_handle_mode(br, mdst->addr.proto) &&
+		    br_multicast_is_star_g(&mdst->addr))
+			allow_mode_include = false;
+	} else {
+		p = NULL;
+	}
+
 	while (p || rp) {
 		struct net_bridge_port *port, *lport, *rport;
 
@@ -292,6 +301,10 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
 						   local_orig);
 				goto delivered;
 			}
+			if ((!allow_mode_include &&
+			     p->filter_mode == MCAST_INCLUDE) ||
+			    (p->flags & MDB_PG_FLAGS_BLOCKED))
+				goto delivered;
 		} else {
 			port = rport;
 		}
-- 
2.25.4