net_sched: check cops->tcf_block in tc_bind_tclass()

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@syzkaller.appspotmail.com
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2019-09-08 12:11:23 -07:00 committed by David S. Miller
parent 94a72b3f02
commit 8b142a00ed
1 changed files with 2 additions and 0 deletions

View File

@ -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;