Subject: Re: nf_nat_pptp 4.12.3 kernel lockup/reboot

From: Florian Westphal <[email-masked]>
Date: Mon, 24 Jul 2017 18:20:39 +0200

Florian Westphal <[email-masked]> wrote:
> Denys Fedoryshchenko <[email-masked]> wrote:
> > Hi,
> > 
> > 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.