From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit acc64f52afac15e9e44d9b5253271346841786e0 ]
The blamed commit made the fatally incorrect assumption that ports which aren't in the FORWARDING STP state should not have packets forwarded towards them, and that is all that needs to be done.
However, that logic alone permits BLOCKING ports to forward to FORWARDING ports, which of course allows packet storms to occur when there is an L2 loop.
The ocelot_get_bridge_fwd_mask should not only ask "what can the bridge do for you", but "what can you do for the bridge". This way, only FORWARDING ports forward to the other FORWARDING ports from the same bridging domain, and we are still compatible with the idea of multiple bridges.
Fixes: df291e54ccca ("net: ocelot: support multiple bridges") Suggested-by: Colin Foster colin.foster@in-advantage.com Reported-by: Colin Foster colin.foster@in-advantage.com Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: Colin Foster colin.foster@in-advantage.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 2948d731a1c1..512dff955166 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -1260,14 +1260,19 @@ static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond, return mask; }
-static u32 ocelot_get_bridge_fwd_mask(struct ocelot *ocelot, +static u32 ocelot_get_bridge_fwd_mask(struct ocelot *ocelot, int src_port, struct net_device *bridge) { + struct ocelot_port *ocelot_port = ocelot->ports[src_port]; u32 mask = 0; int port;
+ if (!ocelot_port || ocelot_port->bridge != bridge || + ocelot_port->stp_state != BR_STATE_FORWARDING) + return 0; + for (port = 0; port < ocelot->num_phys_ports; port++) { - struct ocelot_port *ocelot_port = ocelot->ports[port]; + ocelot_port = ocelot->ports[port];
if (!ocelot_port) continue; @@ -1333,7 +1338,7 @@ void ocelot_apply_bridge_fwd_mask(struct ocelot *ocelot) struct net_device *bridge = ocelot_port->bridge; struct net_device *bond = ocelot_port->bond;
- mask = ocelot_get_bridge_fwd_mask(ocelot, bridge); + mask = ocelot_get_bridge_fwd_mask(ocelot, port, bridge); mask |= cpu_fwd_mask; mask &= ~BIT(port); if (bond) {