net/sched: cls_fw: Fix improper refcount update leads to use-after-free

stable inclusion
from stable-v5.10.187
commit 80e0e8d5f54397c5048fa2274144134dd9dc91b5
category: bugfix
bugzilla: 189032,https://gitee.com/src-openeuler/kernel/issues/I7N3N3
CVE: CVE-2023-3776

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=80e0e8d5f54397c5048fa2274144134dd9dc91b5

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

[ Upstream commit 0323bce598eea038714f941ce2b22541c46d488f ]

In the event of a failure in tcf_change_indev(), fw_set_parms() will
immediately return an error after incrementing or decrementing
reference counter in tcf_bind_filter().  If attacker can control
reference counter to zero and make reference freed, leading to
use after free.

In order to prevent this, move the point of possible failure above the
point where the TC_FW_CLASSID is handled.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reported-by: NM A Ramdhan <ramdhan@starlabs.sg>
Signed-off-by: NM A Ramdhan <ramdhan@starlabs.sg>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: NPedro Tammela <pctammela@mojatatu.com>
Message-ID: <20230705161530.52003-1-ramdhan@starlabs.sg>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NDong Chenchen <dongchenchen2@huawei.com>

net/sched/cls_fw.c

@@ -210,11 +210,6 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 	if (err < 0)
 		return err;
 
-	if (tb[TCA_FW_CLASSID]) {
-		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
-		tcf_bind_filter(tp, &f->res, base);
-	}
-
 	if (tb[TCA_FW_INDEV]) {
 		int ret;
 		ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack);
@@ -231,6 +226,11 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 	} else if (head->mask != 0xFFFFFFFF)
 		return err;
 
+	if (tb[TCA_FW_CLASSID]) {
+		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
+		tcf_bind_filter(tp, &f->res, base);
+	}
+
 	return 0;
 }