net_sched: red: Avoid illegal values

Check the qmin & qmax values doesn't overflow for the given Wlog value.
Check that qmin <= qmax.

Fixes: a783474591f2 ("[PKT_SCHED]: Generic RED layer")
Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 22 insertions, 0 deletions

diff --git a/include/net/red.h b/include/net/red.h
index 5918f78d36a0..9665582c4687 100644
--- a/include/net/red.h
+++ b/include/net/red.h
@@ -168,6 +168,17 @@ static inline void red_set_vars(struct red_vars *v)
 	v->qcount	= -1;
 }
 
+static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog)
+{
+	if (fls(qth_min) + Wlog > 32)
+		return false;
+	if (fls(qth_max) + Wlog > 32)
+		return false;
+	if (qth_max < qth_min)
+		return false;
+	return true;
+}
+
 static inline void red_set_parms(struct red_parms *p,
 				 u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
 				 u8 Scell_log, u8 *stab, u32 max_P)
diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index b30a2c70bd48..531250fceb9e 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -369,6 +369,9 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt)
 
 	ctl = nla_data(tb[TCA_CHOKE_PARMS]);
 
+	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
+		return -EINVAL;
+
 	if (ctl->limit > CHOKE_MAX_QUEUE)
 		return -EINVAL;
 
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 17c7130454bd..bc30f9186ac6 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -356,6 +356,9 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp,
 	struct gred_sched *table = qdisc_priv(sch);
 	struct gred_sched_data *q = table->tab[dp];
 
+	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
+		return -EINVAL;
+
 	if (!q) {
 		table->tab[dp] = q = *prealloc;
 		*prealloc = NULL;
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 7f8ea9e297c3..9d874e60e032 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -212,6 +212,8 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt)
 	max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
 
 	ctl = nla_data(tb[TCA_RED_PARMS]);
+	if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
+		return -EINVAL;
 
 	if (ctl->limit > 0) {
 		child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit);
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 09c1203c1711..930e5bd26d3d 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -639,6 +639,9 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt)
 	if (ctl->divisor &&
 	    (!is_power_of_2(ctl->divisor) || ctl->divisor > 65536))
 		return -EINVAL;
+	if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max,
+					ctl_v1->Wlog))
+		return -EINVAL;
 	if (ctl_v1 && ctl_v1->qth_min) {
 		p = kmalloc(sizeof(*p), GFP_KERNEL);
 		if (!p)