From: Hangyu Hua <hbh25y@gmail.com>
Date: Wed, 7 Jun 2023 02:23:01 +0000 (+0800)
Subject: net: sched: fix possible refcount leak in tc_chain_tmplt_add()
X-Git-Tag: v5.4.247~30
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=198da74a4e8d4c2b2669eebc9f85e19e80cfae5a;p=thirdparty%2Fkernel%2Fstable.git

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 3e5b10bec0cf7..a4cf718bdb8a0 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2732,6 +2732,7 @@ 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;
 	}