This is a note to let you know that I've just added the patch titled net: dsa: Discard frames from unused ports to the 4.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dsa-discard-frames-from-unused-ports.patch and it can be found in the queue-4.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Apr 10 23:19:25 CEST 2018 From: Andrew Lunn <andrew@xxxxxxx> Date: Sat, 7 Apr 2018 20:37:40 +0200 Subject: net: dsa: Discard frames from unused ports From: Andrew Lunn <andrew@xxxxxxx> [ Upstream commit fc5f33768cca7144f8d793205b229d46740d183b ] 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 <cphealy@xxxxxxxxx> Fixes: 91da11f870f0 ("net: Distributed Switch Architecture protocol support") Signed-off-by: Andrew Lunn <andrew@xxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/dsa/dsa_priv.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -126,6 +126,7 @@ static inline struct net_device *dsa_mas 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_mas 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 */ Patches currently in stable-queue which might be from andrew@xxxxxxx are queue-4.16/net-dsa-discard-frames-from-unused-ports.patch