[PATCH net 2/5] net: sched: cls_matchall: Undo tcf_bind_filter in case of failure after mall_set_parms

[Victor Nogueira <victor@mojatatu.com>]

In case an error occurred after mall_set_parms executed successfully, we
must undo the tcf_bind_filter call it issues.

Fix that by calling tcf_unbind_filter in err_replace_hw_filter label.

Fixes: ec2507d2a306 ("net/sched: cls_matchall: Fix error path")

Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
---
 net/sched/cls_matchall.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index fa3bbd187eb9..02830409e013 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -163,7 +163,7 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 			  struct cls_mall_head *head,
 			  unsigned long base, struct nlattr **tb,
 			  struct nlattr *est, u32 flags, u32 fl_flags,
-			  struct netlink_ext_ack *extack)
+			  bool *bound_to_filter, struct netlink_ext_ack *extack)
 {
 	int err;
 
@@ -175,6 +175,7 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 	if (tb[TCA_MATCHALL_CLASSID]) {
 		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 		tcf_bind_filter(tp, &head->res, base);
+		*bound_to_filter = true;
 	}
 	return 0;
 }
@@ -186,6 +187,7 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 		       struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
+	bool bound_to_filter = false;
 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 	struct cls_mall_head *new;
 	u32 userflags = 0;
@@ -227,7 +229,7 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 	}
 
 	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE],
-			     flags, new->flags, extack);
+			     flags, new->flags, &bound_to_filter, extack);
 	if (err)
 		goto err_set_parms;
 
@@ -246,6 +248,8 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 	return 0;
 
 err_replace_hw_filter:
+	if (bound_to_filter)
+		tcf_unbind_filter(tp, &new->res);
 err_set_parms:
 	free_percpu(new->pf);
 err_alloc_percpu:
-- 
2.25.1