Messages in this thread Patch in this message | | | Date | Fri, 24 Feb 2023 11:53:13 -0800 | Subject | [kernel PATCH v2 1/1] Bluetooth: hci_sync: clear workqueue before clear mgmt cmd | From | Zhengping Jiang <> |
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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@google.com> ---
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
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