From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eyal Birger Subject: Re: xfrm, ip tunnel: non released device reference upon device unregistration Date: Sun, 4 Feb 2018 15:32:52 +0200 Message-ID: <20180204153252.29b4c982@jimi> References: <20180204132118.6fef9bf0@jimi> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, herbert@gondor.apana.org.au, davem@davemloft.net, shmulik@metanetworks.com To: steffen.klassert@secunet.com Return-path: Received: from mail-wm0-f44.google.com ([74.125.82.44]:55708 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751594AbeBDNc7 (ORCPT ); Sun, 4 Feb 2018 08:32:59 -0500 Received: by mail-wm0-f44.google.com with SMTP id 143so21169805wma.5 for ; Sun, 04 Feb 2018 05:32:58 -0800 (PST) In-Reply-To: <20180204132118.6fef9bf0@jimi> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 4 Feb 2018 13:21:18 +0200 Eyal Birger wrote: > Hi, > > We've encountered a non released device reference upon device > unregistration which seems to stem from xfrm policy code. > > The setup includes: > - an underlay device (e.g. eth0) using IPv4 > - an xfrm IPv6 over IPv4 tunnel routed via the underlay device > - an ipip6 tunnel over the xfrm IPv6 tunnel > > When tearing down the underlay device, after traffic had passed via > the ipip6 tunnel, log messages of the following form are observed: > > unregister_netdevice: waiting for eth0 to become free. Usage count = 2 > > The below synthetic script reproduces this consistently on a fresh > ubuntu vm running net-next v4.15-6066-ge9522a5: Minor correction: net-next version v4.15-10442-g617aebe Eyal.