From edbde451bf3fddd17cd7fdb43fa668112f7b1440 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 8 Jul 2020 20:13:59 -0700 Subject: [PATCH] net_sched: fix a memory leak in atm_tc_init() [ Upstream commit 306381aec7c2b5a658eebca008c8a1b666536cba ] When tcf_block_get() fails inside atm_tc_init(), atm_tc_put() is called to release the qdisc p->link.q. But the flow->ref prevents it to do so, as the flow->ref is still zero. Fix this by moving the p->link.ref initialization before tcf_block_get(). Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure") Reported-and-tested-by: syzbot+d411cff6ab29cc2c311b@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_atm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c index f4f9b8cdbffb..6385995dc700 100644 --- a/net/sched/sch_atm.c +++ b/net/sched/sch_atm.c @@ -553,16 +553,16 @@ static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt, if (!p->link.q) p->link.q = &noop_qdisc; pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q); + p->link.vcc = NULL; + p->link.sock = NULL; + p->link.common.classid = sch->handle; + p->link.ref = 1; err = tcf_block_get(&p->link.block, &p->link.filter_list, sch, extack); if (err) return err; - p->link.vcc = NULL; - p->link.sock = NULL; - p->link.common.classid = sch->handle; - p->link.ref = 1; tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch); return 0; }