INFO: task syz-executor.2:11778 blocked for more than 140 seconds. Not tainted 4.14.203-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28912 11778 9992 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1731 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 kthread_stop+0xce/0x640 kernel/kthread.c:530 kvm_mmu_pre_destroy_vm+0x41/0x4f arch/x86/kvm/mmu.c:5903 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:770 [inline] kvm_put_kvm+0x30a/0xa90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:807 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:818 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x417811 RSP: 002b:00007ffd3205f080 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000417811 RDX: 0000000000000000 RSI: 0000000000000256 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000054bb6256 R09: 0000000054bb625a R10: 00007ffd3205f160 R11: 0000000000000293 R12: 000000000118c9a0 R13: 000000000118c9a0 R14: 00000000000003e8 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1523: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by agetty/7691: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1523 Comm: khungtaskd Not tainted 4.14.203-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9789 Comm: kworker/u4:10 Not tainted 4.14.203-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff88809291c200 task.stack: ffff888061248000 RIP: 0010:__lock_acquire+0x225/0x3f20 kernel/locking/lockdep.c:3396 RSP: 0018:ffff8880ba407c98 EFLAGS: 00000006 RAX: ffffffff8b9d55d0 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 1ffffffff11f077a RSI: 0000000000000000 RDI: ffffffff88f83bd0 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: ffff88809291c200 R12: ffffffff88f83bc8 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8beb4d40 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c01067d000 CR3: 0000000097d94000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get_update_offsets_now+0xc1/0x3f0 kernel/time/timekeeping.c:2229 hrtimer_update_base kernel/time/hrtimer.c:505 [inline] hrtimer_interrupt+0x364/0x5e0 kernel/time/hrtimer.c:1353 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:796 [inline] RIP: 0010:lock_acquire+0x97/0x3f0 kernel/locking/lockdep.c:3993 RSP: 0018:ffff88806124fc78 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11e1230 RBX: ffff88809291c200 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88809291ca84 RBP: ffffffff88f77500 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88809291c200 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 Code: 4b 8d 7c f4 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5e 2a 00 00 4b 8b 44 f4 08 48 85 c0 0f 84 31 ff ff ff f0 ff 80 38 01 00 00 <49> 8d b3 80 08 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 f1 48