net: fddi: fix UAF in fza_probe

commit deb7178 upstream.

fp is netdev private data and it cannot be
used after free_netdev() call. Using fp after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() after error message.

Fixes: 61414f5 ("FDDI: defza: Add support for DEC FDDIcontroller 700
TURBOchannel adapter")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/fddi/defza.c

@@ -1504,9 +1504,8 @@ static int fza_probe(struct device *bdev)
 	release_mem_region(start, len);
 
 err_out_kfree:
-	free_netdev(dev);
-
 	pr_err("%s: initialization failure, aborting!\n", fp->name);
+	free_netdev(dev);
 	return ret;
 }