From d3fa76ee6b4a8dd0efda4e78e96f5b19533b3dea Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sat, 24 Mar 2007 22:13:06 -0700 Subject: [PATCH] [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 Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/sched/cls_basic.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c index fad08e521c..70fe36eb66 100644 --- a/net/sched/cls_basic.c +++ b/net/sched/cls_basic.c @@ -81,6 +81,13 @@ static void basic_put(struct tcf_proto *tp, unsigned long f) 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 @@ static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle, } 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; -- 2.39.5