[PATCH] net: sched: Fix qdisc_rate_table refcount leak when get tcf_block failed

[Xiyu Yang]

The reference counting issue happens in one exception handling path of
cbq_change_class(). When failing to get tcf_block, the function forgets
to decrease the refcount of "rtab" increased by qdisc_put_rtab(),
causing a refcount leak.

Fix this issue by jumping to "failure" label when get tcf_block failed.

Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
---
 net/sched/sch_cbq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index b79a7e27bb31..38a3a8394bbd 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1614,7 +1614,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
 	err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
 	if (err) {
 		kfree(cl);
-		return err;
+		goto failure;
 	}
 
 	if (tca[TCA_RATE]) {
-- 
2.7.4