From 268bcca1e7b0d244afd07ea89cda672e61b0fc4a Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sat, 9 Feb 2008 03:47:19 -0800 Subject: [PATCH] [PKT_SCHED] ematch: oops from uninitialized variable (resend) Setting up a meta match causes a kernel OOPS because of uninitialized elements in tree. [ 37.322381] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [ 37.322381] IP: [] :em_meta:em_meta_destroy+0x17/0x80 [ 37.322381] Call Trace: [ 37.322381] [] tcf_em_tree_destroy+0x2d/0xa0 [ 37.322381] [] tcf_em_tree_validate+0x2dc/0x4a0 [ 37.322381] [] nla_parse+0x92/0xe0 [ 37.322381] [] :cls_basic:basic_change+0x202/0x3c0 [ 37.322381] [] kmem_cache_alloc+0x67/0xa0 [ 37.322381] [] tc_ctl_tfilter+0x3b1/0x580 [ 37.322381] [] rtnetlink_rcv_msg+0x0/0x260 [ 37.322381] [] netlink_rcv_skb+0x74/0xa0 [ 37.322381] [] rtnetlink_rcv+0x18/0x20 [ 37.322381] [] netlink_unicast+0x263/0x290 [ 37.322381] [] __alloc_skb+0x96/0x160 [ 37.322381] [] netlink_sendmsg+0x274/0x340 [ 37.322381] [] sock_sendmsg+0x12b/0x140 [ 37.322381] [] autoremove_wake_function+0x0/0x30 [ 37.322381] [] autoremove_wake_function+0x0/0x30 [ 37.322381] [] sock_sendmsg+0x12b/0x140 [ 37.322381] [] zone_statistics+0xb1/0xc0 [ 37.322381] [] sys_sendmsg+0x20e/0x360 [ 37.322381] [] sockfd_lookup_light+0x41/0x80 [ 37.322381] [] handle_mm_fault+0x3eb/0x7f0 [ 37.322381] [] system_call_after_swapgs+0x7b/0x80 Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/sched/ematch.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/sched/ematch.c b/net/sched/ematch.c index 74ff918455a2..d421ec728ee7 100644 --- a/net/sched/ematch.c +++ b/net/sched/ematch.c @@ -312,10 +312,9 @@ int tcf_em_tree_validate(struct tcf_proto *tp, struct nlattr *nla, struct tcf_ematch_tree_hdr *tree_hdr; struct tcf_ematch *em; - if (!nla) { - memset(tree, 0, sizeof(*tree)); + memset(tree, 0, sizeof(*tree)); + if (!nla) return 0; - } err = nla_parse_nested(tb, TCA_EMATCH_TREE_MAX, nla, em_policy); if (err < 0) -- 2.20.1