From: Cong Wang <xiyou.wangcong@xxxxxxxxx> [ Upstream commit 8b142a00edcf8422ca48b8de88d286efb500cb53 ] At least sch_red and sch_tbf don't implement ->tcf_block() while still have a non-zero tc "class". Instead of adding nop implementations to each of such qdisc's, we can just relax the check of cops->tcf_block() in tc_bind_tclass(). They don't support TC filter anyway. Reported-by: syzbot+21b29db13c065852f64b@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: Jamal Hadi Salim <jhs@xxxxxxxxxxxx> Cc: Jiri Pirko <jiri@xxxxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/sched/sch_api.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 04faee7ccbce6..1047825d9f48d 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1920,6 +1920,8 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, cl = cops->find(q, portid); if (!cl) return; + if (!cops->tcf_block) + return; block = cops->tcf_block(q, cl, NULL); if (!block) return; -- 2.20.1
