====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc1-next-20241205-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.1250/12292 is trying to acquire lock: ffff88803339c078 (&hdev->lock){+.+.}-{4:4}, at: mgmt_remove_adv_monitor_complete+0xaf/0x550 net/bluetooth/mgmt.c:5524 but task is already holding lock: ffff88803339c690 (&hdev->cmd_sync_work_lock){+.+.}-{4:4}, at: hci_cmd_sync_clear+0x4e/0x220 net/bluetooth/hci_sync.c:658 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&hdev->cmd_sync_work_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 hci_cmd_sync_lookup_entry net/bluetooth/hci_sync.c:838 [inline] hci_cmd_sync_queue_once+0x43/0x240 net/bluetooth/hci_sync.c:782 le_conn_complete_evt+0xae1/0x12e0 net/bluetooth/hci_event.c:5778 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789 hci_event_func net/bluetooth/hci_event.c:7481 [inline] hci_event_packet+0xa55/0x1540 net/bluetooth/hci_event.c:7536 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4039 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&hdev->lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 mgmt_remove_adv_monitor_complete+0xaf/0x550 net/bluetooth/mgmt.c:5524 _hci_cmd_sync_cancel_entry net/bluetooth/hci_sync.c:645 [inline] hci_cmd_sync_clear+0x107/0x220 net/bluetooth/hci_sync.c:660 hci_unregister_dev+0x181/0x510 net/bluetooth/hci_core.c:2694 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->cmd_sync_work_lock); lock(&hdev->lock); lock(&hdev->cmd_sync_work_lock); lock(&hdev->lock); *** DEADLOCK *** 1 lock held by syz.4.1250/12292: #0: ffff88803339c690 (&hdev->cmd_sync_work_lock){+.+.}-{4:4}, at: hci_cmd_sync_clear+0x4e/0x220 net/bluetooth/hci_sync.c:658 stack backtrace: CPU: 1 UID: 0 PID: 12292 Comm: syz.4.1250 Not tainted 6.13.0-rc1-next-20241205-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 mgmt_remove_adv_monitor_complete+0xaf/0x550 net/bluetooth/mgmt.c:5524 _hci_cmd_sync_cancel_entry net/bluetooth/hci_sync.c:645 [inline] hci_cmd_sync_clear+0x107/0x220 net/bluetooth/hci_sync.c:660 hci_unregister_dev+0x181/0x510 net/bluetooth/hci_core.c:2694 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f27e3d7ff19 Code: Unable to access opcode bytes at 0x7f27e3d7feef. RSP: 002b:00007f27e4c0d058 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000019000 RBX: 00007f27e3f46080 RCX: 00007f27e3d7ff19 RDX: 0000000000019000 RSI: 0000000020002fc0 RDI: 000000000000000a RBP: 00007f27e3df3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f27e3f46080 R15: 00007fffb7786898