net_sched: fix a resource leak in tcindex_set_parms()

stable inclusion
from linux-4.19.103
commit 7b3dbf958a1a6ec9e2ef0d3dd58cf0f7964ca8ba

--------------------------------

[ Upstream commit 52b5ae50 ]

Jakub noticed there is a potential resource leak in
tcindex_set_parms(): when tcindex_filter_result_init() fails
and it jumps to 'errout1' which doesn't release the memory
and resources allocated by tcindex_alloc_perfect_hash().

We should just jump to 'errout_alloc' which calls
tcindex_free_perfect_hash().

Fixes: b9a24bb7 ("net_sched: properly handle failure case of tcf_exts_init()")
Reported-by: NJakub Kicinski <kuba@kernel.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/sched/cls_tcindex.c

@@ -365,7 +365,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 
 	err = tcindex_filter_result_init(&new_filter_result);
 	if (err < 0)
-		goto errout1;
+		goto errout_alloc;
 	if (old_r)
 		cr = r->res;
 
@@ -484,7 +484,6 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 		tcindex_free_perfect_hash(cp);
 	else if (balloc == 2)
 		kfree(cp->h);
-errout1:
 	tcf_exts_destroy(&new_filter_result.exts);
 errout:
 	kfree(cp);