From 26aa0459fad28725aa0bc12a3615cc9a0bd7118f Mon Sep 17 00:00:00 2001 From: Jesus Sanchez-Palencia Date: Mon, 16 Oct 2017 18:01:23 -0700 Subject: [PATCH] net/sched: Check for null dev_queue on create flow In qdisc_alloc() the dev_queue pointer was used without any checks being performed. If qdisc_create() gets a null dev_queue pointer, it just passes it along to qdisc_alloc(), leading to a crash. That happens if a root qdisc implements select_queue() and returns a null dev_queue pointer for an "invalid handle", for example, or if the dev_queue associated with the parent qdisc is null. This patch is in preparation for the next in this series, where select_queue() is being added to mqprio and as it may return a null dev_queue. Signed-off-by: Jesus Sanchez-Palencia Tested-by: Henrik Austad Signed-off-by: Jeff Kirsher --- net/sched/sch_generic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 6ced7c89c141..aa74aa42b5d7 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -603,8 +603,14 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, struct Qdisc *sch; unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size; int err = -ENOBUFS; - struct net_device *dev = dev_queue->dev; + struct net_device *dev; + if (!dev_queue) { + err = -EINVAL; + goto errout; + } + + dev = dev_queue->dev; p = kzalloc_node(size, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue));