From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 8 Oct 2018 06:22:41 -0400
Subject: net: sched: cls_u32: the tp_c argument of u32_set_parms() is always
 tp->data
Patch-mainline: v4.20-rc1
Git-commit: db04ff4863bf439500036b1882a9f2236f3c1d76
References: bsc#1109837

It must be tc_u_common associated with that tp (i.e. tp->data).
Proof:
	* both ->ht_up and ->tp_c are assign-once
	* ->tp_c of anything inserted into tp_c->hlist is tp_c
	* hnodes never get reinserted into the lists or moved
between those, so anything found by u32_lookup_ht(tp->data, ...)
will have ->tp_c equal to tp->data.
	* tp->root->tp_c == tp->data.
	* ->ht_up of anything inserted into hnode->ht[...] is
equal to hnode.
	* knodes never get reinserted into hash chains or moved
between those, so anything returned by u32_lookup_key(ht, ...)
will have ->ht_up equal to ht.
	* any knode returned by u32_get(tp, ...) will have ->ht_up->tp_c
point to tp->data

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/cls_u32.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -957,8 +957,7 @@ static int u32_change(struct net *net, s
 		if (!new)
 			return -ENOMEM;
 
-		err = u32_set_parms(net, tp, base,
-				    rtnl_dereference(n->ht_up)->tp_c, new, tb,
+		err = u32_set_parms(net, tp, base, tp_c, new, tb,
 				    tca[TCA_RATE], ovr, extack);
 
 		if (err) {
@@ -1123,7 +1122,7 @@ static int u32_change(struct net *net, s
 	}
 #endif
 
-	err = u32_set_parms(net, tp, base, ht->tp_c, n, tb, tca[TCA_RATE], ovr,
+	err = u32_set_parms(net, tp, base, tp_c, n, tb, tca[TCA_RATE], ovr,
 			    extack);
 	if (err == 0) {
 		struct tc_u_knode __rcu **ins;