From 592eba75ed3d80f968799ecd5d9553bae0b5be8e Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 22 Sep 2020 10:12:30 +0800 Subject: [PATCH] net: sched: cbs: Avoid division by zero when calculating the port rate stable inclusion from linux-4.19.99 commit 172c529cb00acc367426a3aab72ceb8d3c742ca5 -------------------------------- [ Upstream commit 83c8c3cf45163f0c823db37be6ab04dfcf8ac751 ] As explained in the "net: sched: taprio: Avoid division by zero on invalid link speed" commit, it is legal for the ethtool API to return zero as a link speed. So guard against it to ensure we don't perform a division by zero in kernel. Fixes: e0a7683d30e9 ("net/sched: cbs: fix port_rate miscalculation") Signed-off-by: Vladimir Oltean Acked-by: Vinicius Costa Gomes Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang Signed-off-by: Li Aichun Reviewed-by: guodeqing Signed-off-by: Yang Yingliang --- net/sched/sch_cbs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index 7c40b0ff756f..ce7965cc4018 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -311,7 +311,7 @@ static void cbs_set_port_rate(struct net_device *dev, struct cbs_sched_data *q) if (err < 0) goto skip; - if (ecmd.base.speed != SPEED_UNKNOWN) + if (ecmd.base.speed && ecmd.base.speed != SPEED_UNKNOWN) speed = ecmd.base.speed; skip: -- GitLab