====================================================== WARNING: possible circular locking dependency detected 5.15.172-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:3/3605 is trying to acquire lock: ffff0000dae90c28 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}, at: __flush_work+0xd0/0x1c0 kernel/workqueue.c:3090 but task is already holding lock: ffff800016e77228 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_epo+0x58/0x158 net/rfkill/core.c:450 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 rfkill_register+0x44/0x7a4 net/rfkill/core.c:1045 hci_register_dev+0x3e0/0x880 net/bluetooth/hci_core.c:3960 __vhci_create_device drivers/bluetooth/hci_vhci.c:129 [inline] vhci_create_device+0x2c4/0x568 drivers/bluetooth/hci_vhci.c:153 vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline] vhci_write+0x318/0x3b8 drivers/bluetooth/hci_vhci.c:290 call_write_iter include/linux/fs.h:2174 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x884/0xb44 fs/read_write.c:594 ksys_write+0x15c/0x26c fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:656 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #3 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 vhci_send_frame+0x8c/0x10c drivers/bluetooth/hci_vhci.c:71 hci_send_frame+0x194/0x2f0 net/bluetooth/hci_core.c:4256 hci_sched_acl_pkt net/bluetooth/hci_core.c:4781 [inline] hci_sched_acl net/bluetooth/hci_core.c:4866 [inline] hci_tx_work+0x9ac/0x16cc net/bluetooth/hci_core.c:4932 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 -> #2 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: __flush_work+0xf8/0x1c0 kernel/workqueue.c:3090 flush_work+0x24/0x38 kernel/workqueue.c:3115 hci_dev_do_open+0x9c4/0x104c net/bluetooth/hci_core.c:1619 hci_power_on+0x13c/0x65c net/bluetooth/hci_core.c:2265 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 -> #1 (&hdev->req_lock){+.+.}-{3:3}: __mutex_lock_common+0x194/0x2154 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743 hci_req_sync net/bluetooth/hci_request.c:278 [inline] bg_scan_update+0x9c/0x470 net/bluetooth/hci_request.c:2952 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 -> #0 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623 __flush_work+0xf8/0x1c0 kernel/workqueue.c:3090 __cancel_work_timer+0x3ec/0x548 kernel/workqueue.c:3181 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3217 hci_request_cancel_all+0xcc/0x2d0 net/bluetooth/hci_request.c:3522 hci_dev_do_close+0x54/0x1060 net/bluetooth/hci_core.c:1736 hci_rfkill_set_block+0xdc/0x1d0 net/bluetooth/hci_core.c:2235 rfkill_set_block+0x18c/0x37c net/rfkill/core.c:345 rfkill_epo+0x8c/0x158 net/rfkill/core.c:454 __rfkill_handle_global_op net/rfkill/input.c:60 [inline] rfkill_op_handler+0x170/0x288 net/rfkill/input.c:108 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 other info that might help us debug this: Chain exists of: (work_completion)(&hdev->bg_scan_update) --> &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((work_completion)(&hdev->bg_scan_update)); *** DEADLOCK *** 3 locks held by kworker/0:3/3605: #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283 #1: ffff800022877c00 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285 #2: ffff800016e77228 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_epo+0x58/0x158 net/rfkill/core.c:450 stack backtrace: CPU: 0 PID: 3605 Comm: kworker/0:3 Not tainted 5.15.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events rfkill_op_handler Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623 __flush_work+0xf8/0x1c0 kernel/workqueue.c:3090 __cancel_work_timer+0x3ec/0x548 kernel/workqueue.c:3181 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3217 hci_request_cancel_all+0xcc/0x2d0 net/bluetooth/hci_request.c:3522 hci_dev_do_close+0x54/0x1060 net/bluetooth/hci_core.c:1736 hci_rfkill_set_block+0xdc/0x1d0 net/bluetooth/hci_core.c:2235 rfkill_set_block+0x18c/0x37c net/rfkill/core.c:345 rfkill_epo+0x8c/0x158 net/rfkill/core.c:454 __rfkill_handle_global_op net/rfkill/input.c:60 [inline] rfkill_op_handler+0x170/0x288 net/rfkill/input.c:108 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870