====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/5649 is trying to acquire lock: ffff888071375108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:552 but task is already holding lock: ffffffff8ef2ca28 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x16e/0x570 net/rfkill/core.c:1297 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+0x175/0x9d0 kernel/locking/mutex.c:747 rfkill_register+0x3a/0xb30 net/rfkill/core.c:1075 hci_register_dev+0x43a/0xd40 net/bluetooth/hci_core.c:2658 __vhci_create_device+0x393/0x800 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+0x2c7/0x470 drivers/bluetooth/hci_vhci.c:615 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x64f/0xdf0 fs/read_write.c:584 ksys_write+0x12f/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b -> #2 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x175/0x9d0 kernel/locking/mutex.c:747 vhci_send_frame+0x67/0xa0 drivers/bluetooth/hci_vhci.c:78 hci_send_frame+0x220/0x470 net/bluetooth/hci_core.c:3042 hci_sched_acl_pkt net/bluetooth/hci_core.c:3654 [inline] hci_sched_acl net/bluetooth/hci_core.c:3739 [inline] hci_tx_work+0x1456/0x1e40 net/bluetooth/hci_core.c:3838 process_one_work+0x886/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 -> #1 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: __flush_work+0x103/0xa10 kernel/workqueue.c:3403 hci_dev_close_sync+0x22d/0x1160 net/bluetooth/hci_sync.c:4982 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1eb/0x600 net/bluetooth/hci_core.c:2739 vhci_release+0x7f/0x100 drivers/bluetooth/hci_vhci.c:672 __fput+0x270/0xbb0 fs/file_table.c:394 task_work_run+0x14d/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa92/0x2ae0 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021 get_signal+0x23be/0x2790 kernel/signal.c:2904 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x63/0x6b -> #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+0x2464/0x3b10 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5718 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x175/0x9d0 kernel/locking/mutex.c:747 hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:552 hci_rfkill_set_block+0x1b9/0x200 net/bluetooth/hci_core.c:956 rfkill_set_block+0x200/0x550 net/rfkill/core.c:346 rfkill_fop_write+0x2d4/0x570 net/rfkill/core.c:1305 vfs_write+0x2a4/0xdf0 fs/read_write.c:582 ksys_write+0x1f0/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b 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.4/5649: #0: ffffffff8ef2ca28 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x16e/0x570 net/rfkill/core.c:1297 stack backtrace: CPU: 0 PID: 5649 Comm: syz-executor.4 Not tainted 6.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x317/0x400 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+0x2464/0x3b10 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5718 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x175/0x9d0 kernel/locking/mutex.c:747 hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:552 hci_rfkill_set_block+0x1b9/0x200 net/bluetooth/hci_core.c:956 rfkill_set_block+0x200/0x550 net/rfkill/core.c:346 rfkill_fop_write+0x2d4/0x570 net/rfkill/core.c:1305 vfs_write+0x2a4/0xdf0 fs/read_write.c:582 ksys_write+0x1f0/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f9653c7c959 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:00007f96549ba0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9653d9bf80 RCX: 00007f9653c7c959 RDX: 0000000000000008 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007f9653cd8c88 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9653d9bf80 R15: 00007ffeac834858