linux-kernel - [PATCH net] net: bridge: locally receive all multicast packets if IFF

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20250217112621.66916-1-nbd@nbd.name>
Date: Mon, 17 Feb 2025 12:26:20 +0100
From: Felix Fietkau <nbd@....name>
To: netdev@...r.kernel.org,
	Roopa Prabhu <roopa@...dia.com>,
	Nikolay Aleksandrov <razor@...ckwall.org>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>
Cc: bridge@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Subject: [PATCH net] net: bridge: locally receive all multicast packets if IFF_ALLMULTI is set

If multicast snooping is enabled, multicast packets may not always end up on
the local bridge interface, if the host is not a member of the multicast
group. Similar to how IFF_PROMISC allows all packets to be received locally,
let IFF_ALLMULTI allow all multicast packets to be received.

Signed-off-by: Felix Fietkau <nbd@....name>
---
 net/bridge/br_input.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 232133a0fd21..7fa2da6985b5 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -155,6 +155,8 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 			pkt_type = BR_PKT_MULTICAST;
 			if (br_multicast_rcv(&brmctx, &pmctx, vlan, skb, vid))
 				goto drop;
+			if (br->dev->flags & IFF_ALLMULTI)
+				local_rcv = true;
 		}
 	}
 
-- 
2.47.1