[NET_SCHED]: cls_basic: fix NULL pointer dereference
cls_basic doesn't allocate tp->root before it is linked into the
active classifier list, resulting in a NULL pointer dereference
when packets hit the classifier before its ->change function is
called.
Reported by Chris Madden <chris@reflexsecurity.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index fad08e5..70fe36e 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -81,6 +81,13 @@
static int basic_init(struct tcf_proto *tp)
{
+ struct basic_head *head;
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (head == NULL)
+ return -ENOBUFS;
+ INIT_LIST_HEAD(&head->flist);
+ tp->root = head;
return 0;
}
@@ -176,15 +183,6 @@
}
err = -ENOBUFS;
- if (head == NULL) {
- head = kzalloc(sizeof(*head), GFP_KERNEL);
- if (head == NULL)
- goto errout;
-
- INIT_LIST_HEAD(&head->flist);
- tp->root = head;
- }
-
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (f == NULL)
goto errout;