[PATCH 3.18 47/58] net_sched: red: Avoid illegal values

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

3.18-stable review patch.  If anyone has any objections, please let me know.

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

From: Nogah Frankel <nogahf@xxxxxxxxxxxx>


[ Upstream commit 8afa10cbe281b10371fee5a87ab266e48d71a7f9 ]

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@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/net/red.h     |   11 +++++++++++
 net/sched/sch_choke.c |    3 +++
 net/sched/sch_gred.c  |    3 +++
 net/sched/sch_red.c   |    2 ++
 net/sched/sch_sfq.c   |    3 +++
 5 files changed, 22 insertions(+)

--- a/include/net/red.h
+++ b/include/net/red.h
@@ -167,6 +167,17 @@ static inline void red_set_vars(struct r
 	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)
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -431,6 +431,9 @@ static int choke_change(struct Qdisc *sc
 
 	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;
 
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -388,6 +388,9 @@ static inline int gred_change_vq(struct
 	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;
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -199,6 +199,8 @@ static int red_change(struct Qdisc *sch,
 	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);
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -653,6 +653,9 @@ static int sfq_change(struct Qdisc *sch,
 	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)