[NETFILTER]: nf_conntrack: fix invalid conntrack statistics RCU assumption
NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding nf_conntrack_lock.
Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 3deeb90..d59640e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -563,7 +563,7 @@
if (del_timer(&ct->timeout)) {
death_by_timeout((unsigned long)ct);
dropped = 1;
- NF_CT_STAT_INC(early_drop);
+ NF_CT_STAT_INC_ATOMIC(early_drop);
}
nf_ct_put(ct);
return dropped;
@@ -821,7 +821,7 @@
/* Previously seen (loopback or untracked)? Ignore. */
if ((*pskb)->nfct) {
- NF_CT_STAT_INC(ignore);
+ NF_CT_STAT_INC_ATOMIC(ignore);
return NF_ACCEPT;
}
@@ -840,8 +840,8 @@
* core what to do with the packet. */
if (l4proto->error != NULL &&
(ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
- NF_CT_STAT_INC(error);
- NF_CT_STAT_INC(invalid);
+ NF_CT_STAT_INC_ATOMIC(error);
+ NF_CT_STAT_INC_ATOMIC(invalid);
return -ret;
}
@@ -849,13 +849,13 @@
&set_reply, &ctinfo);
if (!ct) {
/* Not valid part of a connection */
- NF_CT_STAT_INC(invalid);
+ NF_CT_STAT_INC_ATOMIC(invalid);
return NF_ACCEPT;
}
if (IS_ERR(ct)) {
/* Too stressed to deal. */
- NF_CT_STAT_INC(drop);
+ NF_CT_STAT_INC_ATOMIC(drop);
return NF_DROP;
}
@@ -868,7 +868,7 @@
DEBUGP("nf_conntrack_in: Can't track with proto module\n");
nf_conntrack_put((*pskb)->nfct);
(*pskb)->nfct = NULL;
- NF_CT_STAT_INC(invalid);
+ NF_CT_STAT_INC_ATOMIC(invalid);
return -ret;
}