Patch "net: dsa: Discard frames from unused ports" has been added to the 4.15-stable tree

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 4.15-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-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Andrew Lunn <[email protected]>
Date: Sat, 7 Apr 2018 20:37:40 +0200
Subject: net: dsa: Discard frames from unused ports

From: Andrew Lunn <[email protected]>

[ 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.

---
 net/dsa/dsa_priv.h |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

@@ -117,6 +117,7 @@ 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;

@@ -128,7 +129,12 @@ 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 [email protected] are

queue-4.15/net-dsa-discard-frames-from-unused-ports.patch