From: Jia Guo <guojia12@xxxxxxxxxx>
Subject: ocfs2: fix a panic problem caused by o2cb_ctl
In the process of creating a node, it will cause NULL pointer dereference
in kernel if o2cb_ctl failed in the interval (mkdir,
o2cb_set_node_attribute(node_num)] in function o2cb_add_node.
The node num is initialized to 0 in function o2nm_node_group_make_item,
o2nm_node_group_drop_item will mistake the node number 0 for a valid node
number when we delete the node before the node number is set correctly.
If the local node number of the current host happens to be 0,
cluster->cl_local_node will be set to O2NM_INVALID_NODE_NUM while
o2hb_thread still running. The panic stack is generated as follows:
o2hb_thread
\-o2hb_do_disk_heartbeat
\-o2hb_check_own_slot
|-slot = ®->hr_slots[o2nm_this_node()];
//o2nm_this_node() return O2NM_INVALID_NODE_NUM
We need to check whether the node number is set when we delete the node.
Link: http://lkml.kernel.org/r/133d8045-72cc-863e-8eae-5013f9f6bc51@xxxxxxxxxx
Signed-off-by: Jia Guo <guojia12@xxxxxxxxxx>
Reviewed-by: Joseph Qi <jiangqi903@xxxxxxxxx>
Acked-by: Jun Piao <piaojun@xxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <ge.changwei@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/cluster/nodemanager.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
--- a/fs/ocfs2/cluster/nodemanager.c~ocfs2-fix-a-panic-problem-caused-by-o2cb_ctl
+++ a/fs/ocfs2/cluster/nodemanager.c
@@ -621,13 +621,15 @@ static void o2nm_node_group_drop_item(st
struct o2nm_node *node = to_o2nm_node(item);
struct o2nm_cluster *cluster = to_o2nm_cluster(group->cg_item.ci_parent);
- o2net_disconnect_node(node);
+ if (cluster->cl_nodes[node->nd_num] == node) {
+ o2net_disconnect_node(node);
- if (cluster->cl_has_local &&
- (cluster->cl_local_node == node->nd_num)) {
- cluster->cl_has_local = 0;
- cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
- o2net_stop_listening(node);
+ if (cluster->cl_has_local &&
+ (cluster->cl_local_node == node->nd_num)) {
+ cluster->cl_has_local = 0;
+ cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
+ o2net_stop_listening(node);
+ }
}
/* XXX call into net to stop this node from trading messages */
_
