Bluetooth: hci2: Opcode 0x0406 failed: -4 Bluetooth: hci2: Opcode 0x0406 failed: -4 Freezing user space processes ------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.2707/13838 is trying to acquire lock: ffffffff8eb4bf40 (console_owner){..-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline] ffffffff8eb4bf40 (console_owner){..-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline] ffffffff8eb4bf40 (console_owner){..-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline] ffffffff8eb4bf40 (console_owner){..-.}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3246 [inline] ffffffff8eb4bf40 (console_owner){..-.}-{0:0}, at: console_flush_all+0x123/0xaf0 kernel/printk/printk.c:3343 but task is already holding lock: ffff888029180a90 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x42/0x260 kernel/sched/core.c:4476 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:572 [inline] try_to_wake_up+0x67/0x14d0 kernel/sched/core.c:4292 __wake_up_common kernel/sched/wait.c:108 [inline] __wake_up_common_lock+0x13a/0x1f0 kernel/sched/wait.c:125 tty_port_default_wakeup+0xc8/0x100 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x70e/0x950 drivers/tty/serial/8250/8250_port.c:1723 serial8250_handle_irq+0x166/0x550 drivers/tty/serial/8250/8250_port.c:1853 serial8250_default_handle_irq+0xbf/0x1e0 drivers/tty/serial/8250/8250_port.c:1867 serial8250_interrupt+0x8d/0x160 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x216/0x9a0 kernel/irq/handle.c:209 handle_irq_event_percpu kernel/irq/handle.c:246 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263 handle_edge_irq+0x1f4/0x8a0 kernel/irq/chip.c:859 generic_handle_irq_desc include/linux/irqdesc.h:188 [inline] handle_irq arch/x86/kernel/irq.c:209 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:280 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:273 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206 spin_unlock_irq include/linux/spinlock.h:402 [inline] __rpm_callback+0xa7/0x950 drivers/base/power/runtime.c:383 rpm_callback drivers/base/power/runtime.c:460 [inline] rpm_resume+0x104d/0x16d0 drivers/base/power/runtime.c:939 rpm_resume+0x8b0/0x16d0 drivers/base/power/runtime.c:917 pm_runtime_work+0x103/0x1b0 drivers/base/power/runtime.c:1004 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&tty->write_wait){-.-.}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 __wake_up_common_lock+0x30/0x1f0 kernel/sched/wait.c:124 tty_port_default_wakeup+0xc8/0x100 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x70e/0x950 drivers/tty/serial/8250/8250_port.c:1723 serial8250_handle_irq+0x166/0x550 drivers/tty/serial/8250/8250_port.c:1853 serial8250_default_handle_irq+0xbf/0x1e0 drivers/tty/serial/8250/8250_port.c:1867 serial8250_interrupt+0x8d/0x160 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x216/0x9a0 kernel/irq/handle.c:209 handle_irq_event_percpu kernel/irq/handle.c:246 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263 handle_edge_irq+0x1f4/0x8a0 kernel/irq/chip.c:859 generic_handle_irq_desc include/linux/irqdesc.h:188 [inline] handle_irq arch/x86/kernel/irq.c:209 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:280 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:273 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:790 [inline] uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline] uart_write+0x3c0/0x9f0 drivers/tty/serial/serial_core.c:630 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0xd49/0x11e0 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write+0x509/0x9c0 drivers/tty/tty_io.c:1081 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 uart_port_lock_irqsave include/linux/serial_core.h:719 [inline] serial8250_console_write+0x153/0x1ba0 drivers/tty/serial/8250/8250_port.c:3344 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x6ea/0xaf0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 register_console+0xbc3/0xfc0 kernel/printk/printk.c:4208 univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:515 console_init+0x10b/0x4a0 kernel/printk/printk.c:4407 start_kernel+0x238/0x3e0 init/main.c:1112 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157 -> #0 (console_owner){..-.}-{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+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 console_lock_spinning_enable kernel/printk/printk.c:1902 [inline] console_emit_next_record kernel/printk/printk.c:3177 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x693/0xaf0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __report_bug+0x349/0x570 lib/bug.c:248 report_bug+0x16a/0x220 lib/bug.c:286 handle_bug+0x9c/0x200 arch/x86/kernel/traps.c:436 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:490 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:593 __set_task_frozen+0x260/0x340 kernel/freezer.c:139 task_call_func+0x1aa/0x260 kernel/sched/core.c:4495 __freeze_task kernel/freezer.c:150 [inline] freeze_task+0x229/0x3b0 kernel/freezer.c:169 try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54 freeze_processes+0xce/0x1e0 kernel/power/process.c:137 suspend_freeze_processes kernel/power/power.h:281 [inline] suspend_prepare kernel/power/suspend.c:387 [inline] enter_state kernel/power/suspend.c:609 [inline] pm_suspend+0x2f1/0x760 kernel/power/suspend.c:644 state_store+0x206/0x290 kernel/power/main.c:819 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: console_owner --> &tty->write_wait --> &p->pi_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->pi_lock); lock(&tty->write_wait); lock(&p->pi_lock); lock(console_owner); *** DEADLOCK *** 10 locks held by syz.6.2707/13838: #0: ffff888077f09b30 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888081b1c450 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #1: ffff888081b1c450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffff888053c1bc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336 #3: ffff88801f28c968 (kn->active#68){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #3: ffff88801f28c968 (kn->active#68){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337 #4: ffffffff8ea02160 (system_transition_mutex){+.+.}-{4:4}, at: enter_state kernel/power/suspend.c:591 [inline] #4: ffffffff8ea02160 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x3c7/0x760 kernel/power/suspend.c:644 #5: ffffffff8e80a058 (tasklist_lock){.+.+}-{3:3}, at: try_to_freeze_tasks+0xe5/0x620 kernel/power/process.c:52 #6: ffffffff8eb7b7b8 (freezer_lock){....}-{3:3}, at: freeze_task+0x7e/0x3b0 kernel/freezer.c:168 #7: ffff888029180a90 (&p->pi_lock){-.-.}-{2:2}, at: task_call_func+0x42/0x260 kernel/sched/core.c:4476 #8: ffffffff8eb4bfa0 (console_lock){+.+.}-{0:0}, at: _printk+0xdd/0x130 kernel/printk/printk.c:2504 #9: ffffffff8ea33838 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline] #9: ffffffff8ea33838 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline] #9: ffffffff8ea33838 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline] #9: ffffffff8ea33838 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3246 [inline] #9: ffffffff8ea33838 (console_srcu){....}-{0:0}, at: console_flush_all+0x123/0xaf0 kernel/printk/printk.c:3343 stack backtrace: CPU: 1 UID: 0 PID: 13838 Comm: syz.6.2707 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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+0x1520/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 console_lock_spinning_enable kernel/printk/printk.c:1902 [inline] console_emit_next_record kernel/printk/printk.c:3177 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x693/0xaf0 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __report_bug+0x349/0x570 lib/bug.c:248 report_bug+0x16a/0x220 lib/bug.c:286 handle_bug+0x9c/0x200 arch/x86/kernel/traps.c:436 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:490 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:593 RIP: 0010:__set_task_frozen+0x260/0x340 kernel/freezer.c:139 Code: 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 90 55 5e ff cc e8 7f 18 15 00 90 0f 0b 90 e9 f7 fe ff ff e8 71 18 15 00 90 <0f> 0b 90 eb 93 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c c3 fd ff ff RSP: 0018:ffffc9000749f9f0 EFLAGS: 00010083 RAX: ffffffff81b1eb8f RBX: ffff888029180000 RCX: 0000000000080000 RDX: ffffc9001dad9000 RSI: 000000000001e2a0 RDI: 000000000001e2a1 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff81b1e930 R12: ffff888029180018 R13: 1ffff11005230003 R14: 0000000000000000 R15: ffff888029180b98 task_call_func+0x1aa/0x260 kernel/sched/core.c:4495 __freeze_task kernel/freezer.c:150 [inline] freeze_task+0x229/0x3b0 kernel/freezer.c:169 try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54 freeze_processes+0xce/0x1e0 kernel/power/process.c:137 suspend_freeze_processes kernel/power/power.h:281 [inline] suspend_prepare kernel/power/suspend.c:387 [inline] enter_state kernel/power/suspend.c:609 [inline] pm_suspend+0x2f1/0x760 kernel/power/suspend.c:644 state_store+0x206/0x290 kernel/power/main.c:819 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f84a199de99 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:00007f84a2785028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f84a1c25fa0 RCX: 00007f84a199de99 RDX: 0000000000000004 RSI: 0000200000000100 RDI: 0000000000000004 RBP: 00007f84a1a33eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84a1c26038 R14: 00007f84a1c25fa0 R15: 00007ffe495b63d8 debug_locks && p->lockdep_depth WARNING: kernel/freezer.c:139 at __set_task_frozen+0x260/0x340 kernel/freezer.c:139, CPU#1: syz.6.2707/13838 Modules linked in: CPU: 1 UID: 0 PID: 13838 Comm: syz.6.2707 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__set_task_frozen+0x260/0x340 kernel/freezer.c:139 Code: 00 80 00 00 89 e8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 90 55 5e ff cc e8 7f 18 15 00 90 0f 0b 90 e9 f7 fe ff ff e8 71 18 15 00 90 <0f> 0b 90 eb 93 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c c3 fd ff ff RSP: 0018:ffffc9000749f9f0 EFLAGS: 00010083 RAX: ffffffff81b1eb8f RBX: ffff888029180000 RCX: 0000000000080000 RDX: ffffc9001dad9000 RSI: 000000000001e2a0 RDI: 000000000001e2a1 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff81b1e930 R12: ffff888029180018 R13: 1ffff11005230003 R14: 0000000000000000 R15: ffff888029180b98 FS: 00007f84a27856c0(0000) GS:ffff88812504e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000019b000 CR3: 000000004ac4a000 CR4: 0000000000350ef0 Call Trace: task_call_func+0x1aa/0x260 kernel/sched/core.c:4495 __freeze_task kernel/freezer.c:150 [inline] freeze_task+0x229/0x3b0 kernel/freezer.c:169 try_to_freeze_tasks+0x190/0x620 kernel/power/process.c:54 freeze_processes+0xce/0x1e0 kernel/power/process.c:137 suspend_freeze_processes kernel/power/power.h:281 [inline] suspend_prepare kernel/power/suspend.c:387 [inline] enter_state kernel/power/suspend.c:609 [inline] pm_suspend+0x2f1/0x760 kernel/power/suspend.c:644 state_store+0x206/0x290 kernel/power/main.c:819 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f84a199de99 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:00007f84a2785028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f84a1c25fa0 RCX: 00007f84a199de99 RDX: 0000000000000004 RSI: 0000200000000100 RDI: 0000000000000004 RBP: 00007f84a1a33eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84a1c26038 R14: 00007f84a1c25fa0 R15: 00007ffe495b63d8