net_sched: fix a use-after-free in sfq

Fixes: 25331d6ce42b ("net: sched: implement qstat helper routines")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 7d14926..52f75a5 100644 (file)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -306,10 +306,10 @@ drop:
                len = qdisc_pkt_len(skb);
                slot->backlog -= len;
                sfq_dec(q, x);
-               kfree_skb(skb);
                sch->q.qlen--;
                qdisc_qstats_drop(sch);
                qdisc_qstats_backlog_dec(sch, skb);
+               kfree_skb(skb);
                return len;
        }