From: Or Gerlitz <ogerlitz@mellanox.com>
Date: Sun, 9 Dec 2018 18:10:24 +0200
Subject: net/sched: cls_flower: Reject duplicated rules also under skip_sw
Patch-mainline: v4.20-rc6
Git-commit: 35cc3cefc4de90001c9137e2d01dd9d06b11acfb
References: bsc#1109837

Currently, duplicated rules are rejected only for skip_hw or "none",
hence allowing users to push duplicates into HW for no reason.

Use the flower tables to protect for that.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reported-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/cls_flower.c |   23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1238,18 +1238,16 @@ static int fl_change(struct net *net, st
 	if (err)
 		goto errout_idr;
 
-	if (!tc_skip_sw(fnew->flags)) {
-		if (!fold && fl_lookup(fnew->mask, &fnew->mkey)) {
-			err = -EEXIST;
-			goto errout_mask;
-		}
-
-		err = rhashtable_insert_fast(&fnew->mask->ht, &fnew->ht_node,
-					     fnew->mask->filter_ht_params);
-		if (err)
-			goto errout_mask;
+	if (!fold && fl_lookup(fnew->mask, &fnew->mkey)) {
+		err = -EEXIST;
+		goto errout_mask;
 	}
 
+	err = rhashtable_insert_fast(&fnew->mask->ht, &fnew->ht_node,
+				     fnew->mask->filter_ht_params);
+	if (err)
+		goto errout_mask;
+
 	if (!tc_skip_hw(fnew->flags)) {
 		err = fl_hw_replace_filter(tp, fnew, extack);
 		if (err)
@@ -1303,9 +1301,8 @@ static int fl_delete(struct tcf_proto *t
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f = arg;
 
-	if (!tc_skip_sw(f->flags))
-		rhashtable_remove_fast(&f->mask->ht, &f->ht_node,
-				       f->mask->filter_ht_params);
+	rhashtable_remove_fast(&f->mask->ht, &f->ht_node,
+			       f->mask->filter_ht_params);
 	__fl_delete(tp, f, extack);
 	*last = list_empty(&head->masks);
 	return 0;