| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 008/133] net_sched: fix a memory leak in atm_tc_init() | Date | Mon, 20 Jul 2020 17:35:55 +0200 |
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From: Cong Wang <xiyou.wangcong@gmail.com>
[ 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 <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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sched/sch_atm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/net/sched/sch_atm.c +++ b/net/sched/sch_atm.c @@ -551,16 +551,16 @@ static int atm_tc_init(struct Qdisc *sch 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; }
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