net: dsa: fix a leaked reference by adding missing of_node_put

The call to of_parse_phandle returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./net/dsa/port.c:294:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 284, but without a corresponding object release within this function.
./net/dsa/dsa2.c:627:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 618, but without a corresponding object release within this function.
./net/dsa/dsa2.c:630:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 618, but without a corresponding object release within this function.
./net/dsa/dsa2.c:636:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 618, but without a corresponding object release within this function.
./net/dsa/dsa2.c:639:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 618, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 6 deletions

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index a1917025e155..410f19148106 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -612,8 +612,8 @@ static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
 {
         struct device_node *ports, *port;
         struct dsa_port *dp;
+        int err = 0;
         u32 reg;
-        int err;
 
         ports = of_get_child_by_name(dn, "ports");
         if (!ports) {
@@ -624,19 +624,23 @@ static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
         for_each_available_child_of_node(ports, port) {
                 err = of_property_read_u32(port, "reg", &reg);
                 if (err)
-                        return err;
+                        goto out_put_node;
 
-                if (reg >= ds->num_ports)
-                        return -EINVAL;
+                if (reg >= ds->num_ports) {
+                        err = -EINVAL;
+                        goto out_put_node;
+                }
 
                 dp = &ds->ports[reg];
 
                 err = dsa_port_parse_of(dp, port);
                 if (err)
-                        return err;
+                        goto out_put_node;
         }
 
-        return 0;
+out_put_node:
+        of_node_put(ports);
+        return err;
 }
 
 static int dsa_switch_parse_member_of(struct dsa_switch *ds,