[PATCH 4.19 10/23] net: sched: fix possible refcount leak in tc_chain_tmplt_add()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Hangyu Hua <hbh25y@gmail.com>

[ Upstream commit 44f8baaf230c655c249467ca415b570deca8df77 ]

try_module_get will be called in tcf_proto_lookup_ops. So module_put needs
to be called to drop the refcount if ops don't implement the required
function.

Fixes: 9f407f1768d3 ("net: sched: introduce chain templates")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/sched/cls_api.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index fdd4af137c9fe..6166bbad97536 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1838,6 +1838,7 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 		return PTR_ERR(ops);
 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
 		NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
+		module_put(ops->owner);
 		return -EOPNOTSUPP;
 	}
 
-- 
2.39.2