From 5438dd45831ee33869779bd1919b05816ae4dbc9 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 27 Aug 2020 10:40:41 -0700 Subject: [PATCH] net_sched: fix error path in red_init() When ->init() fails, ->destroy() is called to clean up. So it is unnecessary to clean up in red_init(), and it would cause some refcount underflow. Fixes: aee9caa03fc3 ("net: sched: sch_red: Add qevents "early_drop" and "mark"") Reported-and-tested-by: syzbot+b33c1cb0a30ebdc8a5f9@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+e5ea5f8a3ecfd4427a1c@syzkaller.appspotmail.com Cc: Petr Machata Signed-off-by: Cong Wang Reviewed-by: Petr Machata Signed-off-by: David S. Miller --- net/sched/sch_red.c | 20 ++++---------------- 1 file changed, 4 insertions(+), 16 deletions(-) diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index deac82f3ad7b..e89fab6ccb34 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -353,23 +353,11 @@ static int red_init(struct Qdisc *sch, struct nlattr *opt, FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP, tb[TCA_RED_EARLY_DROP_BLOCK], extack); if (err) - goto err_early_drop_init; + return err; - err = tcf_qevent_init(&q->qe_mark, sch, - FLOW_BLOCK_BINDER_TYPE_RED_MARK, - tb[TCA_RED_MARK_BLOCK], extack); - if (err) - goto err_mark_init; - - return 0; - -err_mark_init: - tcf_qevent_destroy(&q->qe_early_drop, sch); -err_early_drop_init: - del_timer_sync(&q->adapt_timer); - red_offload(sch, false); - qdisc_put(q->qdisc); - return err; + return tcf_qevent_init(&q->qe_mark, sch, + FLOW_BLOCK_BINDER_TYPE_RED_MARK, + tb[TCA_RED_MARK_BLOCK], extack); } static int red_change(struct Qdisc *sch, struct nlattr *opt,