syzbot is reporting attempt to cancel uninitialized work at mgmt_index_removed() [1], for calling cancel_delayed_work_sync() without INIT_DELAYED_WORK() is not permitted. INIT_DELAYED_WORK() is called from mgmt_init_hdev() via chan->hdev_init() from hci_mgmt_cmd(), but cancel_delayed_work_sync() is unconditionally called from mgmt_index_removed(). Call cancel_delayed_work_sync() only if HCI_MGMT flag was set, for mgmt_init_hdev() sets HCI_MGMT flag when calling INIT_DELAYED_WORK(). Link: https://syzkaller.appspot.com/bug?extid=b8ddd338a8838e581b1c [1] Reported-by: syzbot <syzbot+b8ddd338a8838e581b1c@xxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Fixes: 0ef08313cefdd60d ("Bluetooth: Convert delayed discov_off to hci_sync") --- I can't test this patch due to lack of reproducer. But please review and send to linux.git as soon as possible, for currently syzbot can't test changes for 6.0-rc1 due to this problem (please see "Instances:" table at https://syzkaller.appspot.com/upstream ). syzbot was unable to test linux-next.git since 20220628 due to a different bug. As an unfortunate result, this bug (being there since 20220725) which would have been already found and fixed in linux-next.git arrived at linux.git... net/bluetooth/mgmt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index f0bb2fc883d7..6e31023b84f5 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -8935,6 +8935,8 @@ void mgmt_index_removed(struct hci_dev *hdev) HCI_MGMT_EXT_INDEX_EVENTS); /* Cancel any remaining timed work */ + if (!hci_dev_test_flag(hdev, HCI_MGMT)) + return; cancel_delayed_work_sync(&hdev->discov_off); cancel_delayed_work_sync(&hdev->service_cache); cancel_delayed_work_sync(&hdev->rpa_expired); -- 2.34.1
