zd1211rw, fix oops when ejecting install media

patch e0579d576cb894a4cf3c5af04fbf38e8c1281738 in mainline.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index a9c339ef116a185384ae406aa1f14ad8c635f347..53263015c8f135f9349d104623789b05b8529c72 100644 (file)
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -1041,14 +1041,17 @@ 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);