From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: [PATCH nf-next] netns: add and use net_ns_barrier Date: Tue, 13 Jun 2017 08:16:56 +0200 Message-ID: <20170613061656.GF18283@breakpoint.cc> References: <20170530093812.10712-1-fw@strlen.de> <87y3tcj3n7.fsf@xmission.com> <20170601085259.GA6067@breakpoint.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Westphal , "Eric W. Biederman" , netfilter-devel@vger.kernel.org, Linux Kernel Network Developers To: Cong Wang Return-path: Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org Cong Wang wrote: > On Thu, Jun 1, 2017 at 1:52 AM, Florian Westphal wrote: > > Joe described it nicely, problem is that after unload we may have > > conntracks that still have a nf_conn_help extension attached that > > has a pointer to a structure that resided in the (unloaded) module. > > Why not hold a refcnt for its module? That would work as well. I'm not sure its nice to disallow rmmod of helper modules if they are used by a connection however. Right now you can "rmmod nf_conntrack_foo" at any time and this should work just fine without first having to flush affected conntracks manually.