net_sched: act: Dont increment refcnt on replace

 This is a bug fix. The existing code tries to kill many
 birds with one stone: Handling binding of actions to
 filters, new actions and replacing of action
 attributes. A simple test case to illustrate:

XXXX
 moja@fe1:~$ sudo tc actions add action drop index 12
 moja@fe1:~$ actions get action gact index 12
 action order 1: gact action drop
  random type none pass val 0
  index 12 ref 1 bind 0
 moja@fe1:~$ sudo tc actions replace action ok index 12
 moja@fe1:~$ actions get action gact index 12
 action order 1: gact action drop
  random type none pass val 0
  index 12 ref 2 bind 0
XXXX

The above shows the refcounf being wrongly incremented on replace.
There are more complex scenarios with binding of actions to filters
that i am leaving out that didnt work as well...

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 31157d3e729..f7b45ab8538 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -142,10 +142,13 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla,
 		ret = ACT_P_CREATED;
 	} else {
 		d = to_defact(pc);
-		if (!ovr) {
-			tcf_simp_release(d, bind);
+
+		if (bind)
+			return 0;
+		tcf_simp_release(d, bind);
+		if (!ovr)
 			return -EEXIST;
-		}
+
 		reset_policy(d, defdata, parm);
 	}