From: Vladimir Oltean <olteanv@xxxxxxxxx> [ 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 <olteanv@xxxxxxxxx> Acked-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 289f66b9238d..940e72d6db18 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -310,7 +310,7 @@ 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: -- 2.20.1