[PATCH] zd1211rw, fix oops when ejecting install media

The disconnect function can dereference the net_device structure when it
is never allocated. This is the case when ejecting the device installer.

Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Acked-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index b0684f965761..c755b6923812 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -1044,14 +1044,17 @@ error:
 static void disconnect(struct usb_interface *intf)
 {
         struct net_device *netdev = zd_intf_to_netdev(intf);
-        struct zd_mac *mac = zd_netdev_mac(netdev);
-        struct zd_usb *usb = &mac->chip.usb;
+        struct zd_mac *mac;
+        struct zd_usb *usb;
 
         /* Either something really bad happened, or we're just dealing with
          * a DEVICE_INSTALLER. */
         if (netdev == NULL)
                 return;
 
+        mac = zd_netdev_mac(netdev);
+        usb = &mac->chip.usb;
+
         dev_dbg_f(zd_usb_dev(usb), "\n");
 
         zd_netdev_disconnect(netdev);