parport: fix freeing freed memory

After the reference count becomes 0 when put_device() is called, it will
execute the release callback where we are freeing all the allocated
memory associated with the device. So if we just continue on the error
path then we are again freeing devname and trying to dereference par_dev
which has already been free-ed in the release callback.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/parport/share.c

@@ -892,8 +892,10 @@ parport_register_dev_model(struct parport *port, const char *name,
 	par_dev->dev.release = free_pardevice;
 	par_dev->devmodel = true;
 	ret = device_register(&par_dev->dev);
-	if (ret)
-		goto err_put_dev;
+	if (ret) {
+		put_device(&par_dev->dev);
+		goto err_put_port;
+	}
 
 	/* Chain this onto the list */
 	par_dev->prev = NULL;
@@ -940,8 +942,6 @@ parport_register_dev_model(struct parport *port, const char *name,
 
 	return par_dev;
 
-err_put_dev:
-	put_device(&par_dev->dev);
 err_free_devname:
 	kfree(devname);
 err_free_par_dev: