netfilter: ctnetlink: fix dumping of dying/unconfirmed conntracks

The dumping prematurely stops, it seems the callback argument that
indicates that all entries have been dumped is set after iterating
on the first cpu list. The dumping also may stop before the entire
per-cpu list content is also dumped.

With this patch, conntrack -L dying now shows the dying list content
again.

Fixes: b7779d06 ("netfilter: conntrack: spinlock per cpu to protect special lists.")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_netlink.c

@@ -1163,9 +1163,6 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
 	if (cb->args[2])
 		return 0;
 
-	if (cb->args[0] == nr_cpu_ids)
-		return 0;
-
 	for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {
 		struct ct_pcpu *pcpu;
 
@@ -1194,6 +1191,7 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
 			rcu_read_unlock();
 			if (res < 0) {
 				nf_conntrack_get(&ct->ct_general);
+				cb->args[0] = cpu;
 				cb->args[1] = (unsigned long)ct;
 				spin_unlock_bh(&pcpu->lock);
 				goto out;
@@ -1202,10 +1200,10 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
 		if (cb->args[1]) {
 			cb->args[1] = 0;
 			goto restart;
-		} else
-			cb->args[2] = 1;
+		}
 		spin_unlock_bh(&pcpu->lock);
 	}
+	cb->args[2] = 1;
 out:
 	if (last)
 		nf_ct_put(last);