[NET_SCHED]: Use nla_policy for attribute validation in packet schedulers

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

1 files changed, 10 insertions, 6 deletions

diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 365c7d8b17ab..3a9d226ff1e4 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -356,7 +356,7 @@ static inline int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps)
         struct tc_gred_sopt *sopt;
         int i;
 
-        if (dps == NULL || nla_len(dps) < sizeof(*sopt))
+        if (dps == NULL)
                 return -EINVAL;
 
         sopt = nla_data(dps);
@@ -425,6 +425,12 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp,
         return 0;
 }
 
+static const struct nla_policy gred_policy[TCA_GRED_MAX + 1] = {
+        [TCA_GRED_PARMS]        = { .len = sizeof(struct tc_gred_qopt) },
+        [TCA_GRED_STAB]         = { .len = 256 },
+        [TCA_GRED_DPS]          = { .len = sizeof(struct tc_gred_sopt) },
+};
+
 static int gred_change(struct Qdisc *sch, struct nlattr *opt)
 {
         struct gred_sched *table = qdisc_priv(sch);
@@ -436,7 +442,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt)
         if (opt == NULL)
                 return -EINVAL;
 
-        err = nla_parse_nested(tb, TCA_GRED_MAX, opt, NULL);
+        err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy);
         if (err < 0)
                 return err;
 
@@ -444,9 +450,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt)
                 return gred_change_table_def(sch, opt);
 
         if (tb[TCA_GRED_PARMS] == NULL ||
-            nla_len(tb[TCA_GRED_PARMS]) < sizeof(*ctl) ||
-            tb[TCA_GRED_STAB] == NULL ||
-            nla_len(tb[TCA_GRED_STAB]) < 256)
+            tb[TCA_GRED_STAB] == NULL)
                 return -EINVAL;
 
         err = -EINVAL;
@@ -499,7 +503,7 @@ static int gred_init(struct Qdisc *sch, struct nlattr *opt)
         if (opt == NULL)
                 return -EINVAL;
 
-        err = nla_parse_nested(tb, TCA_GRED_MAX, opt, NULL);
+        err = nla_parse_nested(tb, TCA_GRED_MAX, opt, gred_policy);
         if (err < 0)
                 return err;