From: Florian Westphal <fw@xxxxxxxxx>
Now that conntrack core is allowd to insert clashing entries, make sure
GRE won't set assured flag on NAT_CLASH entries, just like UDP.
Doing so prevents early_drop logic for these entries.
Fixes: d671fd82eaa9 ("netfilter: conntrack: allow insertion clash of gre protocol")
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_conntrack_proto_gre.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index ad6f0ca40cd2..af369e686fc5 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -205,6 +205,8 @@ int nf_conntrack_gre_packet(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct nf_hook_state *state)
{
+ unsigned long status;
+
if (!nf_ct_is_confirmed(ct)) {
unsigned int *timeouts = nf_ct_timeout_lookup(ct);
@@ -217,11 +219,17 @@ int nf_conntrack_gre_packet(struct nf_conn *ct,
ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED];
}
+ status = READ_ONCE(ct->status);
/* If we've seen traffic both ways, this is a GRE connection.
* Extend timeout. */
- if (ct->status & IPS_SEEN_REPLY) {
+ if (status & IPS_SEEN_REPLY) {
nf_ct_refresh_acct(ct, ctinfo, skb,
ct->proto.gre.stream_timeout);
+
+ /* never set ASSURED for IPS_NAT_CLASH, they time out soon */
+ if (unlikely((status & IPS_NAT_CLASH)))
+ return NF_ACCEPT;
+
/* Also, more likely to be important, and not a probe. */
if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
nf_conntrack_event_cache(IPCT_ASSURED, ct);
--
2.30.2
