Marc Dionne <[email protected]> wrote:
> Hi,
>
> I've been seeing issues with 4.7-rc kernels with some of our
> multi-thread test cases. I've bisected it down to this commit:
>
> commit 71d8c47fc653711c41bc3282e5b0e605b3727956
> Author: Pablo Neira Ayuso <[email protected]>
> Date: Sun May 1 00:28:40 2016 +0200
>
> netfilter: conntrack: introduce clash resolution on insertion race
>
>
> .. and verified that reverting the commit restores the expected behaviour.
Does this change help?
Subject: Restrict clash resolution to original direction
diff --git a/net/netfilter/nf_conntrack_core.c
b/net/netfilter/nf_conntrack_core.c
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -721,13 +721,18 @@ __nf_conntrack_confirm(struct sk_buff *skb)
not in the hash. If there is, we lost race. */
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
- zone, net))
- goto out;
+ zone, net)) {
+ nf_ct_add_to_dying_list(ct);
+ ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
+ goto dying;
+ }
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
- zone, net))
- goto out;
+ zone, net)) {
+ nf_ct_add_to_dying_list(ct);
+ goto dying;
+ }
/* Timer relative to confirmation time, not original
setting time, otherwise we'd get timer wrap in
@@ -763,9 +768,6 @@ __nf_conntrack_confirm(struct sk_buff *skb)
IPCT_RELATED : IPCT_NEW, ct);
return NF_ACCEPT;
-out:
- nf_ct_add_to_dying_list(ct);
- ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
dying:
nf_conntrack_double_unlock(hash, reply_hash);
NF_CT_STAT_INC(net, insert_failed);
