From ddeda6ca5f218b668b560d90fc31ae469adbfd92 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 10 Jun 2024 20:00:32 +0900 Subject: [PATCH] Bluetooth: hci_core: cancel all works upon hci_unregister_dev() [ Upstream commit 0d151a103775dd9645c78c97f77d6e2a5298d913 ] syzbot is reporting that calling hci_release_dev() from hci_error_reset() due to hci_dev_put() from hci_error_reset() can cause deadlock at destroy_workqueue(), for hci_error_reset() is called from hdev->req_workqueue which destroy_workqueue() needs to flush. We need to make sure that hdev->{rx_work,cmd_work,tx_work} which are queued into hdev->workqueue and hdev->{power_on,error_reset} which are queued into hdev->req_workqueue are no longer running by the moment destroy_workqueue(hdev->workqueue); destroy_workqueue(hdev->req_workqueue); are called from hci_release_dev(). Call cancel_work_sync() on these work items from hci_unregister_dev() as soon as hdev->list is removed from hci_dev_list. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=da0a9c9721e36db712e8 Signed-off-by: Tetsuo Handa Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/hci_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index b9cf5bc9364c..c8c1cd55c0eb 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3839,7 +3839,11 @@ void hci_unregister_dev(struct hci_dev *hdev) list_del(&hdev->list); write_unlock(&hci_dev_list_lock); + cancel_work_sync(&hdev->rx_work); + cancel_work_sync(&hdev->cmd_work); + cancel_work_sync(&hdev->tx_work); cancel_work_sync(&hdev->power_on); + cancel_work_sync(&hdev->error_reset); if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks)) { hci_suspend_clear_tasks(hdev);