dsa: fix freeing of sparse port allocation

If we have defined a sparse port allocation which is non-contiguous and
contains gaps, the code freeing port_names will just stop when it
encouters a first NULL port_names, which is not right, we should iterate
over all possible number of ports (DSA_MAX_PORTS) until we are done.

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

1 files changed, 5 insertions, 3 deletions

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index aa2ff583b7ed..0eb5d5e76dfb 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -350,9 +350,11 @@ static void dsa_of_free_platform_data(struct dsa_platform_data *pd)
 
         for (i = 0; i < pd->nr_chips; i++) {
                 port_index = 0;
-                while (pd->chip[i].port_names &&
-                        pd->chip[i].port_names[++port_index])
-                        kfree(pd->chip[i].port_names[port_index]);
+                while (port_index < DSA_MAX_PORTS) {
+                        if (pd->chip[i].port_names[port_index])
+                                kfree(pd->chip[i].port_names[port_index]);
+                        port_index++;
+                }
                 kfree(pd->chip[i].rtable);
         }
         kfree(pd->chip);