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, 5 deletions

diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 5c5edf56adbd..11fe1a416433 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -77,16 +77,16 @@ static int tcf_csum_init(struct net *n, struct nlattr *nla, struct nlattr *est,
                                      &csum_idx_gen, &csum_hash_info);
                 if (IS_ERR(pc))
                         return PTR_ERR(pc);
-                p = to_tcf_csum(pc);
                 ret = ACT_P_CREATED;
         } else {
-                p = to_tcf_csum(pc);
-                if (!ovr) {
-                        tcf_hash_release(pc, bind, &csum_hash_info);
+                if (bind)/* dont override defaults */
+                        return 0;
+                tcf_hash_release(pc, bind, &csum_hash_info);
+                if (!ovr)
                         return -EEXIST;
-                }
         }
 
+        p = to_tcf_csum(pc);
         spin_lock_bh(&p->tcf_lock);
         p->tcf_action = parm->action;
         p->update_flags = parm->update_flags;