[PATCH v2] net: dsa: fix a leaked reference by adding missing of_node_put

[Wen Yang]

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.yan...@zte.com.cn>
Reviewed-by: Vivien Didelot <vivien.dide...@gmail.com>
Reviewed-by: "David S. Miller" <da...@davemloft.net>
Cc: Andrew Lunn <and...@lunn.ch>
Cc: Vivien Didelot <vivien.dide...@gmail.com>
Cc: Florian Fainelli <f.faine...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Vivien Didelot <vivien.dide...@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-ker...@vger.kernel.org
---
v2->v1: preserve the reverse christmas tree ordering of variables.

 net/dsa/dsa2.c | 16 ++++++++++------
 net/dsa/port.c |  1 +
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 8c431e0..c00ee464 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,
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 2d7e01b..a6d9a04 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -291,6 +291,7 @@ static struct phy_device *dsa_port_get_phy_device(struct 
dsa_port *dp)
                return ERR_PTR(-EPROBE_DEFER);
        }
 
+       of_node_put(phy_dn);
        return phydev;
 }
 
-- 
2.9.5