net/sched: act_skbedit: fix refcount leak when replace fails

when act_skbedit was converted to use RCU in the data plane, we added an
error path, but we forgot to drop the action refcount in case of failure
during a 'replace' operation:

 # tc actions add action skbedit ptype otherhost pass index 100
 # tc action show action skbedit
 total acts 1

         action order 0: skbedit  ptype otherhost pass
          index 100 ref 1 bind 0
 # tc actions replace action skbedit ptype otherhost drop index 100
 RTNETLINK answers: Cannot allocate memory
 We have an error talking to the kernel
 # tc action show action skbedit
 total acts 1

         action order 0: skbedit  ptype otherhost pass
          index 100 ref 2 bind 0

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

Fixes: c749cdda9089 ("net/sched: act_skbedit: don't use spinlock in the data path")
Signed-off-by: Davide Caratti <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index 64dba3708fce2e096872061bd4405344a957be4b..cfceed28c3331e466782150c7656efda759ef097 100644 (file)
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -189,8 +189,7 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
 
        params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
        if (unlikely(!params_new)) {
-               if (ret == ACT_P_CREATED)
-                       tcf_idr_release(*a, bind);
+               tcf_idr_release(*a, bind);
                return -ENOMEM;
        }