Commit 4e830720 authored Dec 23, 2021 by Xin Xiong Committed by Greg Kroah-Hartman Jan 27, 2022

netfilter: ipt_CLUSTERIP: fix refcount leak in clusterip_tg_check()



[ 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: 06aa151a ("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>

parent ad667456

net/ipv4/netfilter/ipt_CLUSTERIP.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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) {