From d4d6ec6dac07f263f06d847d6f732d6855522845 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sun, 8 Sep 2019 13:40:51 -0700 Subject: [PATCH] sch_hhf: ensure quantum and hhf_non_hh_weight are non-zero 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: syzbot+bc6297c11f19ee807dc2@syzkaller.appspotmail.com Reported-by: syzbot+041483004a7f45f1f20a@syzkaller.appspotmail.com Reported-by: syzbot+55be5f513bed37fc4367@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Cc: Terry Lam Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- 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);