net: dsa: fix dereference on ds->dev before null check error

Currently ds->dev is dereferenced on the assignments of pdata and
np before ds->dev is null checked, hence there is a potential null
pointer dereference on ds->dev.  Fix this by assigning pdata and
np after the ds->dev null pointer sanity check.

Addresses-Coverity: ("Dereference before null check")
Fixes: 7e99e3470172 ("net: dsa: remove dsa_switch_alloc helper")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 1e3ac9b56c89827505b9ceff72acdedb07c75def..214dd703b0ccdc7671bf37f77c98e16fe753b1ed 100644 (file)
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -842,13 +842,16 @@ static int dsa_switch_add(struct dsa_switch *ds)
 
 static int dsa_switch_probe(struct dsa_switch *ds)
 {
-       struct dsa_chip_data *pdata = ds->dev->platform_data;
-       struct device_node *np = ds->dev->of_node;
+       struct dsa_chip_data *pdata;
+       struct device_node *np;
        int err;
 
        if (!ds->dev)
                return -ENODEV;
 
+       pdata = ds->dev->platform_data;
+       np = ds->dev->of_node;
+
        if (!ds->num_ports)
                return -EINVAL;