Subject: [PATCH 22/32] net_sched: add policy validation for action attributes

From: Cong Wang <[email-masked]>
Date: Wed, 18 Sep 2019 18:44:43 -0700

[ Upstream commit 199ce850ce112315cfc68d42b694bcaa27b097b7 ]

Similar to commit 8b4c3cdd9dd8
("net: sched: Add policy validation for tc attributes"), we need
to add proper policy validation for TC action attributes too.

Cc: David Ahern <[email-masked]>
Cc: Jamal Hadi Salim <[email-masked]>
Signed-off-by: Cong Wang <[email-masked]>
Acked-by: Jiri Pirko <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 net/sched/act_api.c | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 4e5d2e9ace5d..061e0d047f4f 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -828,6 +828,15 @@ static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 	return c;
 }
 
+static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
+	[TCA_ACT_KIND]		= { .type = NLA_NUL_STRING,
+				    .len = IFNAMSIZ - 1 },
+	[TCA_ACT_INDEX]		= { .type = NLA_U32 },
+	[TCA_ACT_COOKIE]	= { .type = NLA_BINARY,
+				    .len = TC_COOKIE_MAX_SIZE },
+	[TCA_ACT_OPTIONS]	= { .type = NLA_NESTED },
+};
+
 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 				    struct nlattr *nla, struct nlattr *est,
 				    char *name, int ovr, int bind,
@@ -843,8 +852,8 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 	int err;
 
 	if (name == NULL) {
-		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL,
-						  extack);
+		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
+						  tcf_action_policy, extack);
 		if (err < 0)
 			goto err_out;
 		err = -EINVAL;
@@ -853,18 +862,9 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 			goto err_out;
 		}
-		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
-			NL_SET_ERR_MSG(extack, "TC action name too long");
-			goto err_out;
-		}
-		if (tb[TCA_ACT_COOKIE]) {
-			int cklen = nla_len(tb[TCA_ACT_COOKIE]);
-
-			if (cklen > TC_COOKIE_MAX_SIZE) {
-				NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
-				goto err_out;
-			}
+		nla_strlcpy(act_name, kind, IFNAMSIZ);
 
+		if (tb[TCA_ACT_COOKIE]) {
 			cookie = nla_memdup_cookie(tb);
 			if (!cookie) {
 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
@@ -1095,7 +1095,8 @@ static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
 	int index;
 	int err;
 
-	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
+	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
+					  tcf_action_policy, extack);
 	if (err < 0)
 		goto err_out;
 
@@ -1149,7 +1150,8 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
 
 	b = skb_tail_pointer(skb);
 
-	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
+	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
+					  tcf_action_policy, extack);
 	if (err < 0)
 		goto err_out;
 
@@ -1437,7 +1439,7 @@ static struct nlattr *find_dump_kind(struct nlattr **nla)
 
 	if (tb[1] == NULL)
 		return NULL;
-	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
+	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
 		return NULL;
 	kind = tb2[TCA_ACT_KIND];
 
-- 
2.20.1