[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 --- commit f1b9a0694552e18e7a43c292d21abe3b51dfcae2 tree f5ae39c1746fdc1ffbee6c1d90d035ee48ca4904 parent 0a14fe6e5efd0af0f9c6c01e0433445d615d0110 author Patrick McHardy Tue, 20 Mar 2007 16:08:54 +0100 committer Patrick McHardy Tue, 20 Mar 2007 16:08:54 +0100 net/sched/cls_basic.c | 16 +++++++--------- 1 files changed, 7 insertions(+), 9 deletions(-) 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 void basic_put(struct tcf_proto * 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 } 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;