====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/2330 is trying to acquire lock: ffff8881083410b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x1c/0x60 net/bluetooth/hci_core.c:552 but task is already holding lock: ffffffff8377cc68 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x92/0x1f0 net/rfkill/core.c:1278 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0xab/0xa10 kernel/locking/mutex.c:747 rfkill_register+0x26/0x320 net/rfkill/core.c:1057 hci_register_dev+0x17f/0x3f0 net/bluetooth/hci_core.c:2656 __vhci_create_device+0x10d/0x270 drivers/bluetooth/hci_vhci.c:437 vhci_create_device drivers/bluetooth/hci_vhci.c:478 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:535 [inline] vhci_write+0x112/0x1b0 drivers/bluetooth/hci_vhci.c:615 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x25c/0x510 fs/read_write.c:584 ksys_write+0x70/0xf0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0xab/0xa10 kernel/locking/mutex.c:747 vhci_send_frame+0x36/0x70 drivers/bluetooth/hci_vhci.c:78 hci_send_frame+0x6e/0x120 net/bluetooth/hci_core.c:3039 hci_sched_acl_pkt net/bluetooth/hci_core.c:3651 [inline] hci_sched_acl net/bluetooth/hci_core.c:3736 [inline] hci_tx_work+0x6eb/0x8d0 net/bluetooth/hci_core.c:3835 process_one_work+0x208/0x4c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x1c3/0x380 kernel/workqueue.c:2784 kthread+0xde/0x110 kernel/kthread.c:388 ret_from_fork+0x2c/0x40 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #1 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: __flush_work+0x8c/0x4e0 kernel/workqueue.c:3403 hci_dev_close_sync+0xc4/0x5a0 net/bluetooth/hci_sync.c:4982 hci_dev_do_close+0x24/0x60 net/bluetooth/hci_core.c:554 hci_unregister_dev+0xb8/0x1d0 net/bluetooth/hci_core.c:2737 vhci_release+0x3a/0x70 drivers/bluetooth/hci_vhci.c:672 __fput+0xe8/0x280 fs/file_table.c:384 task_work_run+0x55/0x80 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x371/0xbb0 kernel/exit.c:874 do_group_exit+0x32/0xa0 kernel/exit.c:1024 get_signal+0xde7/0xe00 kernel/signal.c:2892 arch_do_signal_or_restart+0x39/0x290 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x110/0x1b0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&hdev->req_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x12e6/0x1d00 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0xcd/0x2d0 kernel/locking/lockdep.c:5718 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0xab/0xa10 kernel/locking/mutex.c:747 hci_dev_do_close+0x1c/0x60 net/bluetooth/hci_core.c:552 hci_rfkill_set_block+0x53/0x80 net/bluetooth/hci_core.c:956 rfkill_set_block+0x86/0x150 net/rfkill/core.c:345 rfkill_fop_write+0x154/0x1f0 net/rfkill/core.c:1286 vfs_write+0xe6/0x510 fs/read_write.c:582 ksys_write+0xbb/0xf0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &hdev->req_lock --> &data->open_mutex --> rfkill_global_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rfkill_global_mutex); lock(&data->open_mutex); lock(rfkill_global_mutex); lock(&hdev->req_lock); *** DEADLOCK *** 1 lock held by syz-executor.0/2330: #0: ffffffff8377cc68 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x92/0x1f0 net/rfkill/core.c:1278 stack backtrace: CPU: 0 PID: 2330 Comm: syz-executor.0 Not tainted 6.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x5c/0xb0 lib/dump_stack.c:106 check_noncircular+0x116/0x130 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x12e6/0x1d00 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0xcd/0x2d0 kernel/locking/lockdep.c:5718 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0xab/0xa10 kernel/locking/mutex.c:747 hci_dev_do_close+0x1c/0x60 net/bluetooth/hci_core.c:552 hci_rfkill_set_block+0x53/0x80 net/bluetooth/hci_core.c:956 rfkill_set_block+0x86/0x150 net/rfkill/core.c:345 rfkill_fop_write+0x154/0x1f0 net/rfkill/core.c:1286 vfs_write+0xe6/0x510 fs/read_write.c:582 ksys_write+0xbb/0xf0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4d0a27cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4d0b0be0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4d0a39bf80 RCX: 00007f4d0a27cae9 RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f4d0a2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000006 R14: 00007f4d0a39bf80 R15: 00007ffd264e8138