From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: nf_nat_pptp 4.12.3 kernel lockup/reboot Date: Fri, 25 Aug 2017 07:21:37 +0200 Message-ID: <20170825052137.GF15739@breakpoint.cc> References: <69c0c47e920e763bce702521baae9caa@nuclearcat.com> <20170724161944.GB23964@breakpoint.cc> <20170724162039.GC23964@breakpoint.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Westphal , Linux Kernel Network Developers To: Denys Fedoryshchenko Return-path: Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:39096 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829AbdHYFYO (ORCPT ); Fri, 25 Aug 2017 01:24:14 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Denys Fedoryshchenko wrote: > >>> I am trying to upgrade kernel 4.11.8 to 4.12.3 (it is a nat/router, handling > >>> approx 2gbps of pppoe users traffic) and noticed that after while server > >>> rebooting(i have set reboot on panic and etc). > >>> I can't run serial console, and in pstore / netconsole there is nothing. > >>> Best i got is some very short message about softlockup in ipmi, but as > >>> storage very limited there - it is near useless. > >>> > >>> By preliminary testing (can't do it much, as it's production) - it seems > >>> following lines causing issue, they worked in 4.11.8 and no more in 4.12.3. > >> > >>Wild guess here, does this help? > >> > >>diff --git a/net/netfilter/nf_conntrack_helper.c > >>b/net/netfilter/nf_conntrack_helper.c > >>--- a/net/netfilter/nf_conntrack_helper.c > >>+++ b/net/netfilter/nf_conntrack_helper.c > >>@@ -266,6 +266,8 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, > >>struct nf_conn *tmpl, > >> help = nf_ct_helper_ext_add(ct, helper, flags); > >> if (help == NULL) > >> return -ENOMEM; > >>+ if (!nf_ct_ext_add(ct, NF_CT_EXT_NAT, flags)); > > > >sigh, stupid typo, should be no ';' at the end above. > Sorry, is there any plans to push this to 4.12 stable queue? No, sorry, this patch adds the extension for all connections that use a helper, but the nat extension is only used/required by pptp helper (and masquerade). Thing is that this patch should not be needed, I will have to review pptp again, maybe i missed a case where the extension is not added. Do you happen to have an oops backtrace? That might speed this up a bit.