====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/2313 is trying to acquire lock: ffff88810f2f90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] ffff88810f2f90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_rfkill_set_block+0x5e/0xe0 net/bluetooth/hci_core.c:956 but task is already holding lock: ffffffff83761560 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xad/0x1e0 net/rfkill/core.c:1298 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+0x99/0x980 kernel/locking/mutex.c:747 rfkill_register+0x24/0x300 net/rfkill/core.c:1075 hci_register_dev+0x188/0x370 net/bluetooth/hci_core.c:2656 __vhci_create_device drivers/bluetooth/hci_vhci.c:437 [inline] vhci_create_device+0x151/0x290 drivers/bluetooth/hci_vhci.c:478 vhci_get_user drivers/bluetooth/hci_vhci.c:535 [inline] vhci_write+0x136/0x190 drivers/bluetooth/hci_vhci.c:615 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x266/0x2e0 fs/read_write.c:584 ksys_write+0x70/0xe0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 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+0x99/0x980 kernel/locking/mutex.c:747 vhci_send_frame+0x38/0x70 drivers/bluetooth/hci_vhci.c:78 hci_send_frame+0x8b/0x100 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+0x2b1/0x810 net/bluetooth/hci_core.c:3835 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x24c/0x4d0 kernel/workqueue.c:2703 worker_thread+0x23d/0x300 kernel/workqueue.c:2784 kthread+0xe5/0x100 kernel/kthread.c:388 ret_from_fork+0x2e/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+0x77/0x470 kernel/workqueue.c:3403 hci_dev_close_sync+0xf0/0x600 net/bluetooth/hci_sync.c:4982 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_unregister_dev+0xd5/0x200 net/bluetooth/hci_core.c:2737 vhci_release+0x3b/0x70 drivers/bluetooth/hci_vhci.c:672 __fput+0xfc/0x270 fs/file_table.c:384 task_work_run+0x7d/0xa0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x2df/0xa50 kernel/exit.c:874 do_group_exit+0x85/0xa0 kernel/exit.c:1024 get_signal+0x77b/0x830 kernel/signal.c:2892 arch_do_signal_or_restart+0x89/0x2b0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop+0x6a/0xe0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x9a/0xe0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x62/0x230 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 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+0x136e/0x2660 kernel/locking/lockdep.c:5136 lock_acquire+0xea/0x260 kernel/locking/lockdep.c:5753 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x99/0x980 kernel/locking/mutex.c:747 hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] hci_rfkill_set_block+0x5e/0xe0 net/bluetooth/hci_core.c:956 rfkill_set_block+0x82/0x140 net/rfkill/core.c:346 rfkill_fop_write+0x190/0x1e0 net/rfkill/core.c:1306 vfs_write+0xe5/0x2e0 fs/read_write.c:582 ksys_write+0x70/0xe0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 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.0/2313: #0: ffffffff83761560 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xad/0x1e0 net/rfkill/core.c:1298 stack backtrace: CPU: 0 PID: 2313 Comm: syz-executor.0 Not tainted 6.6.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x8d/0xe0 lib/dump_stack.c:106 print_circular_bug+0x32a/0x360 kernel/locking/lockdep.c:2060 check_noncircular+0x113/0x130 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+0x136e/0x2660 kernel/locking/lockdep.c:5136 lock_acquire+0xea/0x260 kernel/locking/lockdep.c:5753 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x99/0x980 kernel/locking/mutex.c:747 hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] hci_rfkill_set_block+0x5e/0xe0 net/bluetooth/hci_core.c:956 rfkill_set_block+0x82/0x140 net/rfkill/core.c:346 rfkill_fop_write+0x190/0x1e0 net/rfkill/core.c:1306 vfs_write+0xe5/0x2e0 fs/read_write.c:582 ksys_write+0x70/0xe0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f63f287cae9 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:00007f63f36700c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f63f299bf80 RCX: 00007f63f287cae9 RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f63f28c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000006 R14: 00007f63f299bf80 R15: 00007ffed98978a8