[PATCH net] net/sched: act_ipt: fix refcount leak when replace fails

[Davide Caratti]

After commit 4e8ddd7f1758 ("net: sched: don't release reference on action
overwrite"), the error path of all actions was converted to drop refcount
also when the action was being overwritten. But we forgot act_ipt_init(),
in case allocation of 'tname' was not successful:

 # tc action add action xt -j LOG --log-prefix hello index 100
 tablename: mangle hook: NF_IP_POST_ROUTING
         target:  LOG level warning prefix "hello" index 100
 # tc action show action xt
 total acts 1

         action order 0: tablename: mangle  hook: NF_IP_POST_ROUTING
         target  LOG level warning prefix "hello"
         index 100 ref 1 bind 0
 # tc action replace action xt -j LOG --log-prefix world index 100
 tablename: mangle hook: NF_IP_POST_ROUTING
         target:  LOG level warning prefix "world" index 100
 RTNETLINK answers: Cannot allocate memory
 We have an error talking to the kernel
 # tc action show action xt
 total acts 1

         action order 0: tablename: mangle  hook: NF_IP_POST_ROUTING
         target  LOG level warning prefix "hello"
         index 100 ref 2 bind 0

Ensure we call tcf_idr_release(), in case 'tname' allocation failed, also
when the action is being replaced.

Fixes: 4e8ddd7f1758 ("net: sched: don't release reference on action overwrite")
Signed-off-by: Davide Caratti <dcara...@redhat.com>
---
 net/sched/act_ipt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index 8af6c11d2482..faa1addf89b3 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -199,8 +199,7 @@ static int __tcf_ipt_init(struct net *net, unsigned int id, 
struct nlattr *nla,
 err2:
        kfree(tname);
 err1:
-       if (ret == ACT_P_CREATED)
-               tcf_idr_release(*a, bind);
+       tcf_idr_release(*a, bind);
        return err;
 }
 
-- 
2.20.1