Commit 7a02ea65 authored by Dan Carpenter's avatar Dan Carpenter Committed by David S. Miller

net: sched: prevent a use after free

The bug is that we call kfree_skb(skb) and then pass "skb" to
qdisc_pkt_len(skb) on the next line, which is a use after free.
Also Cong Wang points out that it's better to delay the actual
frees until we drop the rtnl lock so we should use rtnl_kfree_skbs()
instead of kfree_skb().

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: ec97ecf1 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 86b18aaa
...@@ -349,9 +349,9 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, ...@@ -349,9 +349,9 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt,
while (sch->q.qlen > sch->limit) { while (sch->q.qlen > sch->limit) {
struct sk_buff *skb = fq_pie_qdisc_dequeue(sch); struct sk_buff *skb = fq_pie_qdisc_dequeue(sch);
kfree_skb(skb);
len_dropped += qdisc_pkt_len(skb); len_dropped += qdisc_pkt_len(skb);
num_dropped += 1; num_dropped += 1;
rtnl_kfree_skbs(skb, skb);
} }
qdisc_tree_reduce_backlog(sch, num_dropped, len_dropped); qdisc_tree_reduce_backlog(sch, num_dropped, len_dropped);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment