[patch 13/38] PKT_SCHED: ematch: oops from uninitialized variable(resend)

From: Greg KH
Date: Fri Feb 22 2008 - 19:39:36 EST


2.6.24-stable review patch. If anyone has any objections, please let us
know.

------------------
Upstream commit: 268bcca1e7b0d244afd07ea89cda672e61b0fc4a

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: [<ffffffff883fc717>] :em_meta:em_meta_destroy+0x17/0x80

[ 37.322381] Call Trace:
[ 37.322381] [<ffffffff803ec83d>] tcf_em_tree_destroy+0x2d/0xa0
[ 37.322381] [<ffffffff803ecc8c>] tcf_em_tree_validate+0x2dc/0x4a0
[ 37.322381] [<ffffffff803f06d2>] nla_parse+0x92/0xe0
[ 37.322381] [<ffffffff883f9672>] :cls_basic:basic_change+0x202/0x3c0
[ 37.322381] [<ffffffff802a3917>] kmem_cache_alloc+0x67/0xa0
[ 37.322381] [<ffffffff803ea221>] tc_ctl_tfilter+0x3b1/0x580
[ 37.322381] [<ffffffff803dffd0>] rtnetlink_rcv_msg+0x0/0x260
[ 37.322381] [<ffffffff803ee944>] netlink_rcv_skb+0x74/0xa0
[ 37.322381] [<ffffffff803dffc8>] rtnetlink_rcv+0x18/0x20
[ 37.322381] [<ffffffff803ee6c3>] netlink_unicast+0x263/0x290
[ 37.322381] [<ffffffff803cf276>] __alloc_skb+0x96/0x160
[ 37.322381] [<ffffffff803ef014>] netlink_sendmsg+0x274/0x340
[ 37.322381] [<ffffffff803c7c3b>] sock_sendmsg+0x12b/0x140
[ 37.322381] [<ffffffff8024de90>] autoremove_wake_function+0x0/0x30
[ 37.322381] [<ffffffff8024de90>] autoremove_wake_function+0x0/0x30
[ 37.322381] [<ffffffff803c7c3b>] sock_sendmsg+0x12b/0x140
[ 37.322381] [<ffffffff80288611>] zone_statistics+0xb1/0xc0
[ 37.322381] [<ffffffff803c7e5e>] sys_sendmsg+0x20e/0x360
[ 37.322381] [<ffffffff803c7411>] sockfd_lookup_light+0x41/0x80
[ 37.322381] [<ffffffff8028d04b>] handle_mm_fault+0x3eb/0x7f0
[ 37.322381] [<ffffffff8020c2fb>] system_call_after_swapgs+0x7b/0x80

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
net/sched/ematch.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/net/sched/ematch.c
+++ b/net/sched/ematch.c
@@ -305,10 +305,9 @@ int tcf_em_tree_validate(struct tcf_prot
struct tcf_ematch_tree_hdr *tree_hdr;
struct tcf_ematch *em;

- if (!rta) {
- memset(tree, 0, sizeof(*tree));
+ memset(tree, 0, sizeof(*tree));
+ if (!rta)
return 0;
- }

if (rtattr_parse_nested(tb, TCA_EMATCH_TREE_MAX, rta) < 0)
goto errout;

--
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