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, 5 insertions, 3 deletions

diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 03b67674169c..7aa2dcd989f8 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -84,10 +84,12 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
                 ret = ACT_P_CREATED;
         } else {
                 p = to_pedit(pc);
-                if (!ovr) {
-                        tcf_hash_release(pc, bind, &pedit_hash_info);
+                tcf_hash_release(pc, bind, &pedit_hash_info);
+                if (bind)
+                        return 0;
+                if (!ovr)
                         return -EEXIST;
-                }
+
                 if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
                         keys = kmalloc(ksize, GFP_KERNEL);
                         if (keys == NULL)