sch_htb: fix null pointer dereference on a null new_q

sch_htb: fix null pointer dereference on a null new_q

Currently if new_q is null, the null new_q pointer will be
dereference when 'q->offload' is true. Fix this by adding
a braces around htb_parent_to_leaf_offload() to avoid it.

Addresses-Coverity: ("Dereference after null check")
Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload")

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 62e12cb..081c11d 100644 (file)
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1675,9 +1675,10 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg,
                                          cl->parent->common.classid,
                                          NULL);
                if (q->offload) {
-                       if (new_q)
+                       if (new_q) {
                                htb_set_lockdep_class_child(new_q);
-                       htb_parent_to_leaf_offload(sch, dev_queue, new_q);
+                               htb_parent_to_leaf_offload(sch, dev_queue, new_q);
+                       }
                }
        }