Subject: [PATCH AUTOSEL 5.5 126/542] netfilter: flowtable: Fix hardware flush order on nf_flow_table_cleanup

From: Sasha Levin <[email-masked]>
Date: Fri, 14 Feb 2020 10:41:58 -0500

From: Paul Blakey <[email-masked]>

[ Upstream commit 91bfaa15a379e9af24f71fb4ee08d8019b6e8ec7 ]

On netdev down event, nf_flow_table_cleanup() is called for the relevant
device and it cleans all the tables that are on that device.
If one of those tables has hardware offload flag,
nf_flow_table_iterate_cleanup flushes hardware and then runs the gc.
But the gc can queue more hardware work, which will take time to execute.

Instead first add the work, then flush it, to execute it now.

Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <[email-masked]>
Signed-off-by: Pablo Neira Ayuso <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 net/netfilter/nf_flow_table_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 640a46fd710d2..ec402baf16d64 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -530,9 +530,9 @@ static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
 static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
 					  struct net_device *dev)
 {
-	nf_flow_table_offload_flush(flowtable);
 	nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
 	flush_delayed_work(&flowtable->gc_work);
+	nf_flow_table_offload_flush(flowtable);
 }
 
 void nf_flow_table_cleanup(struct net_device *dev)
-- 
2.20.1