Subject: [PATCH 11/21] sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero

From: Cong Wang <[email-masked]>
Date: Sun, 8 Sep 2019 13:40:51 -0700

[ Upstream commit d4d6ec6dac07f263f06d847d6f732d6855522845 ]

In case of TCA_HHF_NON_HH_WEIGHT or TCA_HHF_QUANTUM is zero,
it would make no progress inside the loop in hhf_dequeue() thus
kernel would get stuck.

Fix this by checking this corner case in hhf_change().

Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc")
Reported-by: [email-masked]
Reported-by: [email-masked]
Reported-by: [email-masked]
Cc: Jamal Hadi Salim <[email-masked]>
Cc: Jiri Pirko <[email-masked]>
Cc: Terry Lam <[email-masked]>
Signed-off-by: Cong Wang <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/sched/sch_hhf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index cee6971c1c82..23cd1c873a2c 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -531,7 +531,7 @@ static int hhf_change(struct Qdisc *sch, struct nlattr *opt,
 		new_hhf_non_hh_weight = nla_get_u32(tb[TCA_HHF_NON_HH_WEIGHT]);
 
 	non_hh_quantum = (u64)new_quantum * new_hhf_non_hh_weight;
-	if (non_hh_quantum > INT_MAX)
+	if (non_hh_quantum == 0 || non_hh_quantum > INT_MAX)
 		return -EINVAL;
 
 	sch_tree_lock(sch);
-- 
2.21.0