====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc5-syzkaller-00134-g3f7168591ebf #0 Not tainted ------------------------------------------------------ syz-executor504/5074 is trying to acquire lock: ffff888078f80e10 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xfa/0xa10 kernel/workqueue.c:3400 but task is already holding lock: ffff888078f81108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:552 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&hdev->req_lock){+.+.}-{3:3}: __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_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a -> #2 (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_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a -> #1 (&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:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 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 -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 __flush_work+0x103/0xa10 kernel/workqueue.c:3400 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_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_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a other info that might help us debug this: Chain exists of: (work_completion)(&hdev->tx_work) --> rfkill_global_mutex --> &hdev->req_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->req_lock); lock(rfkill_global_mutex); lock(&hdev->req_lock); lock((work_completion)(&hdev->tx_work)); *** DEADLOCK *** 2 locks held by syz-executor504/5074: #0: ffffffff8ef2dae8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x16e/0x570 net/rfkill/core.c:1297 #1: ffff888078f81108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:552 stack backtrace: CPU: 1 PID: 5074 Comm: syz-executor504 Not tainted 6.7.0-rc5-syzkaller-00134-g3f7168591ebf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 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:3869 [inline] __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 __flush_work+0x103/0xa10 kernel/workqueue.c:3400 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_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_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x62/0xe0 arch/x86/entry/common.c:321 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x70/0x7a RIP: 0023:0xf7ed1579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ffc278dc EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000200002c0 RDX: 0000000000000008 RSI: 00000000f7f93bfc RDI: 00000000f7eec8f6 RBP: 00000000ffc27954 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi