Bluetooth: hci3: Opcode 0x0c1a failed: -4 Bluetooth: hci3: Error when powering off device on rfkill (-4) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.9478/8300 is trying to acquire lock: ffff888064522040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] ffff888064522040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] ffff888064522040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4183 [inline] ffff888064522040 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 kernel/workqueue.c:4241 but task is already holding lock: ffff888064522338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&conn->lock#2){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 l2cap_info_timeout+0x60/0xa0 net/bluetooth/l2cap_core.c:1669 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:3955 [inline] start_flush_work kernel/workqueue.c:4209 [inline] __flush_work+0x700/0xc50 kernel/workqueue.c:4241 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4397 l2cap_conn_del+0x402/0x5b0 net/bluetooth/l2cap_core.c:1797 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5327 hci_dev_do_close+0x30/0xc0 net/bluetooth/hci_core.c:501 hci_rfkill_set_block+0x1f4/0x290 net/bluetooth/hci_core.c:929 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301 vfs_write+0x29a/0xb90 fs/read_write.c:684 ksys_write+0x150/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&conn->lock#2); lock((work_completion)(&(&conn->info_timer)->work)); lock(&conn->lock#2); lock((work_completion)(&(&conn->info_timer)->work)); *** DEADLOCK *** 6 locks held by syz.2.9478/8300: #0: ffffffff8fabecc8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_write+0x19a/0x5a0 net/rfkill/core.c:1293 #1: ffff88805ff48ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x28/0xc0 net/bluetooth/hci_core.c:499 #2: ffff88805ff480c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5315 #3: ffffffff8f934bc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline] #3: ffffffff8f934bc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637 #4: ffff888064522338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763 #5: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #5: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4183 [inline] #5: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 kernel/workqueue.c:4241 stack backtrace: CPU: 1 UID: 0 PID: 8300 Comm: syz.2.9478 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 touch_work_lockdep_map kernel/workqueue.c:3955 [inline] start_flush_work kernel/workqueue.c:4209 [inline] __flush_work+0x700/0xc50 kernel/workqueue.c:4241 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4397 l2cap_conn_del+0x402/0x5b0 net/bluetooth/l2cap_core.c:1797 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5327 hci_dev_do_close+0x30/0xc0 net/bluetooth/hci_core.c:501 hci_rfkill_set_block+0x1f4/0x290 net/bluetooth/hci_core.c:929 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301 vfs_write+0x29a/0xb90 fs/read_write.c:684 ksys_write+0x150/0x270 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3961f9acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3962ef5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3962216090 RCX: 00007f3961f9acb9 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000007 RBP: 00007f3962008bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3962216128 R14: 00007f3962216090 R15: 00007ffed3d5cc98