From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [PATCH] ipvs: changes related to service usecnt Date: Sun, 19 Sep 2010 20:48:00 +0900 Message-ID: <20100919114758.GA18134@verge.net.au> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Patrick McHardy , lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org To: Julian Anastasov Return-path: Content-Disposition: inline In-Reply-To: Sender: lvs-devel-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org On Sat, Sep 18, 2010 at 05:18:46PM +0300, Julian Anastasov wrote: > > Change the usage of svc usecnt during command execution: > > - we check if svc is registered but we do not need to hold usecnt > reference while under __ip_vs_mutex, only the packet handling needs > it during scheduling > > - change __ip_vs_service_get to __ip_vs_service_find and > __ip_vs_svc_fwm_get to __ip_vs_svc_fwm_find because now caller > will increase svc->usecnt > > - put common code that calls update_service in __ip_vs_update_dest > > - put common code in ip_vs_unlink_service() and use it to unregister > the service > > - add comment that svc should not be accessed after ip_vs_del_service > anymore > > - all IP_VS_WAIT_WHILE calls are now unified: usecnt > 0 > > - Properly log the app ports > > As result, some problems are fixed: > > - possible use-after-free of svc in ip_vs_genl_set_cmd after > ip_vs_del_service because our usecnt reference does not guarantee that > svc is not freed on refcnt==0, eg. when no dests are moved to trash > > - possible usecnt leak in do_ip_vs_set_ctl after ip_vs_del_service > when the service is not freed now, for example, when some > destionations are moved into trash and svc->refcnt remains above 0. > It is harmless because svc is not in hash anymore. > > Signed-off-by: Julian Anastasov Hi Julian, thats a pretty big patch to review, but it looks good to me. Acked-by: Simon Horman