dsa: make dsa_switch_setup check for valid port names

This patch changes dsa_switch_setup() to ensure that at least one valid
valid port name is specified and will bail out with an error in case we
walked the maximum number of port with a valid port name found.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 45295ca09571..2bc62ea857c8 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -80,6 +80,7 @@ dsa_switch_setup(struct dsa_switch_tree *dst, int index,
         int ret;
         char *name;
         int i;
+        bool valid_name_found = false;
 
         /*
          * Probe for switch model.
@@ -131,8 +132,13 @@ dsa_switch_setup(struct dsa_switch_tree *dst, int index,
                 } else {
                         ds->phys_port_mask |= 1 << i;
                 }
+                valid_name_found = true;
         }
 
+        if (!valid_name_found && i == DSA_MAX_PORTS) {
+                ret = -EINVAL;
+                goto out;
+        }
 
         /*
          * If the CPU connects to this switch, set the switch tree