net/sched: fix idr leak in the error path of tcf_simp_init()

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>

diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 425eac1..b1f3806 100644 (file)
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -121,7 +121,7 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla,
                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;