From fc5f33768cca7144f8d793205b229d46740d183b Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Sat, 7 Apr 2018 20:37:40 +0200 Subject: [PATCH] net: dsa: Discard frames from unused ports The Marvell switches under some conditions will pass a frame to the host with the port being the CPU port. Such frames are invalid, and should be dropped. Not dropping them can result in a crash when incrementing the receive statistics for an invalid port. Reported-by: Chris Healy Fixes: 91da11f870f0 ("net: Distributed Switch Architecture protocol support") Signed-off-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/dsa_priv.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 70de7895e5b8..053731473c99 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -126,6 +126,7 @@ static inline struct net_device *dsa_master_find_slave(struct net_device *dev, struct dsa_port *cpu_dp = dev->dsa_ptr; struct dsa_switch_tree *dst = cpu_dp->dst; struct dsa_switch *ds; + struct dsa_port *slave_port; if (device < 0 || device >= DSA_MAX_SWITCHES) return NULL; @@ -137,7 +138,12 @@ static inline struct net_device *dsa_master_find_slave(struct net_device *dev, if (port < 0 || port >= ds->num_ports) return NULL; - return ds->ports[port].slave; + slave_port = &ds->ports[port]; + + if (unlikely(slave_port->type != DSA_PORT_TYPE_USER)) + return NULL; + + return slave_port->slave; } /* port.c */ -- 2.30.2