net: sched: fix possible refcount leak in tc_chain_tmplt_add()

[ 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>

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index b51d80a..abaf753 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2780,6 +2780,7 @@ 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;
        }