[NET_SCHED]: Use nla_policy for attribute validation in ematches

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/em_meta.c

@@ -745,6 +745,10 @@ static inline int meta_is_supported(struct meta_value *val)
 	return (!meta_id(val) || meta_ops(val)->get);
 }
 
+static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
+	[TCA_EM_META_HDR]	= { .len = sizeof(struct tcf_meta_hdr) },
+};
+
 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
 			  struct tcf_ematch *m)
 {
@@ -753,13 +757,12 @@ static int em_meta_change(struct tcf_proto *tp, void *data, int len,
 	struct tcf_meta_hdr *hdr;
 	struct meta_match *meta = NULL;
 
-	err = nla_parse(tb, TCA_EM_META_MAX, data, len, NULL);
+	err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy);
 	if (err < 0)
 		goto errout;
 
 	err = -EINVAL;
-	if (tb[TCA_EM_META_HDR] == NULL ||
-	    nla_len(tb[TCA_EM_META_HDR]) < sizeof(*hdr))
+	if (tb[TCA_EM_META_HDR] == NULL)
 		goto errout;
 	hdr = nla_data(tb[TCA_EM_META_HDR]);
 

net/sched/ematch.c

@@ -282,6 +282,11 @@ static int tcf_em_validate(struct tcf_proto *tp,
 	return err;
 }
 
+static const struct nla_policy em_policy[TCA_EMATCH_TREE_MAX + 1] = {
+	[TCA_EMATCH_TREE_HDR]	= { .len = sizeof(struct tcf_ematch_tree_hdr) },
+	[TCA_EMATCH_TREE_LIST]	= { .type = NLA_NESTED },
+};
+
 /**
  * tcf_em_tree_validate - validate ematch config TLV and build ematch tree
  *
@@ -312,7 +317,7 @@ int tcf_em_tree_validate(struct tcf_proto *tp, struct nlattr *nla,
 		return 0;
 	}
 
-	err = nla_parse_nested(tb, TCA_EMATCH_TREE_MAX, nla, NULL);
+	err = nla_parse_nested(tb, TCA_EMATCH_TREE_MAX, nla, em_policy);
 	if (err < 0)
 		goto errout;
 
@@ -323,10 +328,6 @@ int tcf_em_tree_validate(struct tcf_proto *tp, struct nlattr *nla,
 	if (rt_hdr == NULL || rt_list == NULL)
 		goto errout;
 
-	if (nla_len(rt_hdr) < sizeof(*tree_hdr) ||
-	    nla_len(rt_list) < sizeof(*rt_match))
-		goto errout;
-
 	tree_hdr = nla_data(rt_hdr);
 	memcpy(&tree->hdr, tree_hdr, sizeof(*tree_hdr));