net_sched: drr: check for NULL pointer in drr_dequeue

There are cases where qdisc_dequeue_peeked can return NULL, and the result
is dereferenced later on in the function.

Similarly to the other qdisc dequeue functions, check whether the skb
pointer is NULL and if it is, goto out.

Signed-off-by: Bernie Harris <bernie.harris@alliedtelesis.co.nz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Bernie Harris 2016-01-28 16:30:51 +13:00 committed by David S. Miller
parent b83ef507d9
commit df3eb6cd68

View File

@ -403,6 +403,8 @@ static struct sk_buff *drr_dequeue(struct Qdisc *sch)
if (len <= cl->deficit) {
cl->deficit -= len;
skb = qdisc_dequeue_peeked(cl->qdisc);
if (unlikely(skb == NULL))
goto out;
if (cl->qdisc->q.qlen == 0)
list_del(&cl->alist);