On 01/07/13 10:59, Gao feng wrote: > On 01/07/13 10:38, Pablo Neira Ayuso wrote: >> On Mon, Jan 07, 2013 at 03:15:17AM +0100, Pablo Neira Ayuso wrote: >>> Hi Gao, >>> >>> On Mon, Jan 07, 2013 at 09:27:37AM +0800, Gao feng wrote: >>>> Hi Pablo, >>>> >>>> On 01/05/13 11:50, Pablo Neira Ayuso wrote: >>>>> Hi Gao, >>>>> >>>>> On Fri, Dec 28, 2012 at 10:36:46AM +0800, Gao feng wrote: >>>>>> Currectly we unregister proto before all conntrack entries of >>>>>> this proto being destroyed. so in function destroy_conntrack >>>>>> we can't find proper l4proto to call l4proto->destroy. >>>>>> this will cause resource leak. >>>>> >>>>> Good catch. >>>>> >>>>> But better to remove the entries before unregistering the protocol >>>>> tracker, so l4proto->destroy is always called. >>>>> >>>> >>>> I think the reason we unregister proto before remove all entries >>>> is to avoid new entry for this protocol being created. >>>> >>>> If we remove all contrack entries before unregistration, there maybe >>>> some new entries being created between nf_ct_iterate_cleanup and >>>> nf_conntrack_l4proto_unregister_net.this will cause some terrible things. >>> >>> Leaks are less likely to happen, but may well still happen while >>> racing with protocol removal, agreed. >>> >>>> SO I think we should make proto unavailable first,remove all entries next, >>>> and remove proto from nf_ct_protos arrays finally. >>> >>> Your proposal adds a branch in the packet path to fix an issue that is >>> specific of the GRE protocol tracker. In the current code, this fixes >>> the memory leak while removing the nf_conntrack_proto_gre module, >>> which is a rare operation. >>> >>> We have to come with a less intrusive solution. >> >> Wait. The existing code is calling nf_ct_gre_keymap_flush in >> proto_gre_net_exit path, so those keymap objects are not leaked. > > Agree, it looks like nf_ct_gre_keymap_flush is added to solve this > problem. > > Please ignore this patch. I mean ignore the codes of gre part. I still think nf_ct_iterate_cleanup doesn't make sure all entries being destroyed. I will resend this patch. Thanks! -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
