net: Fix oops in dev_ifsioc()

A command like this: "brctl addif br1 eth1" issued as a user gave me
an oops when bridge module wasn't loaded. It's caused by using a dev
pointer before checking for NULL.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 048cf1197872..daca72e6b37b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3745,11 +3745,13 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
 {
         int err;
         struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
-        const struct net_device_ops *ops = dev->netdev_ops;
+        const struct net_device_ops *ops;
 
         if (!dev)
                 return -ENODEV;
 
+        ops = dev->netdev_ops;
+
         switch (cmd) {
                 case SIOCSIFFLAGS:      /* Set interface flags */
                         return dev_change_flags(dev, ifr->ifr_flags);