====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc6-syzkaller-gaafe7ad77b91 #0 Not tainted ------------------------------------------------------ syz-executor419/6094 is trying to acquire lock: ffff0000d95d4e10 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xd0/0x1c0 kernel/workqueue.c:3400 but task is already holding lock: ffff0000d95d5108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] ffff0000d95d5108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_rfkill_set_block+0xe8/0x20c net/bluetooth/hci_core.c:956 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+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799 hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] hci_rfkill_set_block+0xe8/0x20c net/bluetooth/hci_core.c:956 rfkill_set_block+0x18c/0x37c net/rfkill/core.c:346 rfkill_fop_write+0x578/0x734 net/rfkill/core.c:1305 vfs_write+0x2a0/0x910 fs/read_write.c:582 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 -> #2 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799 rfkill_register+0x44/0x7d4 net/rfkill/core.c:1075 hci_register_dev+0x3e0/0x954 net/bluetooth/hci_core.c:2658 __vhci_create_device drivers/bluetooth/hci_vhci.c:437 [inline] vhci_create_device+0x358/0x6c4 drivers/bluetooth/hci_vhci.c:478 vhci_get_user drivers/bluetooth/hci_vhci.c:535 [inline] vhci_write+0x318/0x3b8 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+0x610/0x910 fs/read_write.c:584 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 -> #1 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799 vhci_send_frame+0x8c/0x10c drivers/bluetooth/hci_vhci.c:78 hci_send_frame+0x1c4/0x35c 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+0xba0/0x18e4 net/bluetooth/hci_core.c:3838 process_one_work+0x694/0x1204 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2781 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857 -> #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+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5754 __flush_work+0xf8/0x1c0 kernel/workqueue.c:3400 flush_work+0x24/0x38 kernel/workqueue.c:3425 hci_dev_close_sync+0x1c8/0xf30 net/bluetooth/hci_sync.c:4982 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_rfkill_set_block+0xf0/0x20c net/bluetooth/hci_core.c:956 rfkill_set_block+0x18c/0x37c net/rfkill/core.c:346 rfkill_fop_write+0x578/0x734 net/rfkill/core.c:1305 vfs_write+0x2a0/0x910 fs/read_write.c:582 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 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-executor419/6094: #0: ffff80009122cca8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x234/0x734 net/rfkill/core.c:1297 #1: ffff0000d95d5108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] #1: ffff0000d95d5108 (&hdev->req_lock){+.+.}-{3:3}, at: hci_rfkill_set_block+0xe8/0x20c net/bluetooth/hci_core.c:956 stack backtrace: CPU: 0 PID: 6094 Comm: syz-executor419 Not tainted 6.7.0-rc6-syzkaller-gaafe7ad77b91 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060 check_noncircular+0x310/0x404 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+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5754 __flush_work+0xf8/0x1c0 kernel/workqueue.c:3400 flush_work+0x24/0x38 kernel/workqueue.c:3425 hci_dev_close_sync+0x1c8/0xf30 net/bluetooth/hci_sync.c:4982 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_rfkill_set_block+0xf0/0x20c net/bluetooth/hci_core.c:956 rfkill_set_block+0x18c/0x37c net/rfkill/core.c:346 rfkill_fop_write+0x578/0x734 net/rfkill/core.c:1305 vfs_write+0x2a0/0x910 fs/read_write.c:582 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595