If the flow timer expires, the gc sets on the NF_FLOW_TEARDOWN flag.
Otherwise, the flowtable software path might race to refresh the
timeout, leaving the state machine in inconsistent state.
Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <paulb@xxxxxxxxxxxx>
Reviewed-by: Roi Dayan <roid@xxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_flow_table_core.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 4344e572b7f9..42da6e337276 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -284,7 +284,7 @@ static void flow_offload_del(struct nf_flowtable *flow_table,
if (nf_flow_has_expired(flow))
flow_offload_fixup_ct(flow->ct);
- else if (test_bit(NF_FLOW_TEARDOWN, &flow->flags))
+ else
flow_offload_fixup_ct_timeout(flow->ct);
flow_offload_free(flow);
@@ -361,8 +361,10 @@ static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
{
struct nf_flowtable *flow_table = data;
- if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct) ||
- test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
+ if (nf_flow_has_expired(flow) || nf_ct_is_dying(flow->ct))
+ set_bit(NF_FLOW_TEARDOWN, &flow->flags);
+
+ if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
if (test_bit(NF_FLOW_HW, &flow->flags)) {
if (!test_bit(NF_FLOW_HW_DYING, &flow->flags))
nf_flow_offload_del(flow_table, flow);
--
2.20.1
