[PATCH 5.4 101/320] netfilter: ipt_CLUSTERIP: fix refcount leak in clusterip_tg_check()

Greg Kroah-Hartman
2022-01-24T19:33:11Z

From: Xin Xiong <xiongx18@fudan.edu.cn>

[ Upstream commit d94a69cb2cfa77294921aae9afcfb866e723a2da ]

The issue takes place in one error path of clusterip_tg_check(). When
memcmp() returns nonzero, the function simply returns the error code,
forgetting to decrease the reference count of a clusterip_config
object, which is bumped earlier by clusterip_config_find_get(). This
may incur reference count leak.

Fix this issue by decrementing the refcount of the object in specific
error path.

Fixes: 06aa151ad1fc74 ("netfilter: ipt_CLUSTERIP: check MAC address when duplicate config is set")
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/netfilter/ipt_CLUSTERIP.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index 6bdb1ab8af617..63ebb87d85331 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -505,8 +505,11 @@ static int clusterip_tg_check(const struct xt_tgchk_param *par)
if (IS_ERR(config))
return PTR_ERR(config);
}
- } else if (memcmp(&config->clustermac, &cipinfo->clustermac, ETH_ALEN))
+ } else if (memcmp(&config->clustermac, &cipinfo->clustermac, ETH_ALEN)) {
+ clusterip_config_entry_put(config);
+ clusterip_config_put(config);
return -EINVAL;
+ }

ret = nf_ct_netns_get(par->net, par->family);
if (ret < 0) {
--
2.34.1