INFO: task syz-executor198:5080 blocked for more than 143 seconds. Not tainted 6.2.0-rc5-next-20230127-syzkaller-08766-ge2f86c02fdc9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor198 state:D stack:26888 pid:5080 ppid:5079 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5301 [inline] __schedule+0x245a/0x5a60 kernel/sched/core.c:6619 schedule+0xde/0x1a0 kernel/sched/core.c:6695 schedule_timeout+0x276/0x2b0 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common+0x1ce/0x5c0 kernel/sched/completion.c:106 __flush_workqueue+0x3f5/0x13a0 kernel/workqueue.c:2962 nbd_start_device_ioctl drivers/block/nbd.c:1420 [inline] __nbd_ioctl drivers/block/nbd.c:1482 [inline] nbd_ioctl+0x30b/0xcf0 drivers/block/nbd.c:1522 blkdev_ioctl+0x375/0x800 block/ioctl.c:616 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7facfa8a4379 RSP: 002b:00007ffd37510248 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007facfa8a4379 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd375103e8 R09: 00007ffd375103e8 R10: 00007ffd375103e8 R11: 0000000000000246 R12: 00007facfa863690 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c794970 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c794670 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/28: #0: ffffffff8c795540 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6544 2 locks held by kworker/u5:1/4395: #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff88801ee1c938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x86d/0x1820 kernel/workqueue.c:2361 #1: ffffc90006607da8 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1820 kernel/workqueue.c:2365 2 locks held by getty/4757: #0: ffff88802c0ea098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc5-next-20230127-syzkaller-08766-ge2f86c02fdc9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x316/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x38f/0x440 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xe53/0x11b0 kernel/hung_task.c:377 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1059 Comm: kworker/u4:5 Not tainted 6.2.0-rc5-next-20230127-syzkaller-08766-ge2f86c02fdc9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:x2apic_send_IPI+0x9a/0xe0 arch/x86/kernel/apic/x2apic_phys.c:49 Code: ae f0 0f ae e8 b9 00 04 00 00 41 83 fc 02 44 89 e0 48 0f 44 c1 48 c1 e2 20 b9 30 08 00 00 48 09 d0 48 c1 ea 20 0f 30 66 90 5b <5d> 41 5c c3 5b 31 d2 48 89 c6 bf 30 08 00 00 5d 41 5c e9 af 71 10 RSP: 0018:ffffc9000532f8d8 EFLAGS: 00000202 RAX: 00000001000000fb RBX: ffff888017251d40 RCX: 0000000000000830 RDX: 0000000000000001 RSI: 00000000000000fb RDI: ffffffff8c1049c8 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000000000fb R13: ffffc9000532f910 R14: ffff8880b983d410 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055988e235600 CR3: 000000000c571000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:108 [inline] send_call_function_single_ipi+0x17e/0x1e0 kernel/sched/core.c:3831 smp_call_function_many_cond+0xc82/0xe30 kernel/smp.c:756 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:942 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1770 [inline] text_poke_bp_batch+0x3f1/0x6b0 arch/x86/kernel/alternative.c:2014 text_poke_flush arch/x86/kernel/alternative.c:2129 [inline] text_poke_flush arch/x86/kernel/alternative.c:2126 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2136 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_disable_cpuslocked+0x156/0x1b0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate mm/kfence/core.c:804 [inline] toggle_allocation_gate+0x143/0x230 mm/kfence/core.c:791 process_one_work+0x9bf/0x1820 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.225 msecs