Clear cmd_sync_work queue before clearing the mgmt cmd list to avoid
racing conditions which cause use-after-free.
When powering off the adapter, the mgmt cmd list will be cleared. If a
work is queued in the cmd_sync_work queue at the same time, it will
cause the risk of use-after-free, as the cmd pointer is not checked
before use.
Signed-off-by: Zhengping Jiang <jiangzp@xxxxxxxxxx>
---
Changes in v2:
- Add function to clear the queue without stop the timer
Changes in v1:
- Clear cmd_sync_work queue before clearing the mgmt cmd list
net/bluetooth/hci_sync.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 117eedb6f709..b70365dfff0c 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -636,6 +636,23 @@ void hci_cmd_sync_init(struct hci_dev *hdev)
INIT_DELAYED_WORK(&hdev->adv_instance_expire, adv_timeout_expire);
}
+static void hci_pend_cmd_sync_clear(struct hci_dev *hdev)
+{
+ struct hci_cmd_sync_work_entry *entry, *tmp;
+
+ mutex_lock(&hdev->cmd_sync_work_lock);
+ list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list) {
+ if (entry->destroy) {
+ hci_req_sync_lock(hdev);
+ entry->destroy(hdev, entry->data, -ECANCELED);
+ hci_req_sync_unlock(hdev);
+ }
+ list_del(&entry->list);
+ kfree(entry);
+ }
+ mutex_unlock(&hdev->cmd_sync_work_lock);
+}
+
void hci_cmd_sync_clear(struct hci_dev *hdev)
{
struct hci_cmd_sync_work_entry *entry, *tmp;
@@ -4842,8 +4859,10 @@ int hci_dev_close_sync(struct hci_dev *hdev)
if (!auto_off && hdev->dev_type == HCI_PRIMARY &&
!hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
- hci_dev_test_flag(hdev, HCI_MGMT))
+ hci_dev_test_flag(hdev, HCI_MGMT)) {
+ hci_pend_cmd_sync_clear(hdev);
__mgmt_power_off(hdev);
+ }
hci_inquiry_cache_flush(hdev);
hci_pend_le_actions_clear(hdev);
--
2.39.2.722.g9855ee24e9-goog
