From: Davide Caratti <dcaratti@redhat.com>
Date: Mon, 19 Mar 2018 15:31:23 +0100
Subject: net/sched: fix idr leak in the error path of tcf_simp_init()
Patch-mainline: v4.16-rc7
Git-commit: 60e10b3adc3bac0f6a894c28e0eb1f2d13607362
References: bsc#1109837

if the kernel fails to duplicate 'sdata', creation of a new action fails
with -ENOMEM. However, subsequent attempts to install the same action
using the same value of 'index' systematically fail with -ENOSPC, and
that value of 'index' will no more be usable by act_simple, until rmmod /
insmod of act_simple.ko is done:

 # tc actions add action simple sdata hello index 100
 # tc actions list action simple

        action order 0: Simple <hello>
         index 100 ref 1 bind 0
 # tc actions flush action simple
 # tc actions add action simple sdata hello index 100
 RTNETLINK answers: Cannot allocate memory
 We have an error talking to the kernel
 # tc actions flush action simple
 # tc actions add action simple sdata hello index 100
 RTNETLINK answers: No space left on device
 We have an error talking to the kernel
 # tc actions add action simple sdata hello index 100
 RTNETLINK answers: No space left on device
 We have an error talking to the kernel
 ...

Fix this in the error path of tcf_simp_init(), calling tcf_idr_release()
in place of tcf_idr_cleanup().

Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR")
Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/act_simple.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -121,7 +121,7 @@ static int tcf_simp_init(struct net *net
 		d = to_defact(*a);
 		ret = alloc_defdata(d, defdata);
 		if (ret < 0) {
-			tcf_idr_cleanup(*a, est);
+			tcf_idr_release(*a, bind);
 			return ret;
 		}
 		d->tcf_action = parm->action;