INFO: task syz.3.1880:12641 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1880 state:D stack:26120 pid:12641 tgid:12641 ppid:5809 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common+0x2d7/0x4c0 kernel/sched/completion.c:100 __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x49/0x60 kernel/sched/completion.c:153 __flush_work+0x7d7/0xcc0 kernel/workqueue.c:4277 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4397 hci_cmd_sync_clear+0x33/0x100 net/bluetooth/hci_sync.c:655 hci_unregister_dev+0x1cc/0x640 net/bluetooth/hci_core.c:2711 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:973 do_group_exit+0xd3/0x2a0 kernel/exit.c:1114 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c607c2005 RSP: 002b:00007f4c5e9f5f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f4c609e5fa0 RCX: 00007f4c607c2005 RDX: 00007f4c5e9f5fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4c60813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f4c609e6038 R14: 00007f4c609e5fa0 R15: 00007ffef94d93a8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c9460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c9460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c9460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5574: #0: ffff888036b110a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/u9:4/5817: #0: ffff888029d0c948 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90003e97c90 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff888029290ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331 3 locks held by syz.6.3299/17957: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf14/0x1140 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: c6 6e 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 38 22 00 fb f4 cc 2f 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 0000000005d8f003 RBX: 0000000000000000 RCX: ffffffff8b6826d9 RDX: 0000000000000000 RSI: ffffffff8dac0c73 RDI: ffffffff8bf22a80 RBP: fffffbfff1c12f50 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: 00000000ffffffff R12: 0000000000000000 R13: ffffffff8e097a80 R14: ffffffff908750d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124956000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f201ff8 CR3: 000000003495a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4d0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 bridge0: port 1(bridge_slave_0) entered learning state bridge0: port 2(bridge_slave_1) entered learning state