INFO: task syz-executor.1:10792 blocked for more than 140 seconds. Not tainted 4.14.267-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28912 10792 8010 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 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:555 kvm_mmu_pre_destroy_vm+0x41/0x50 arch/x86/kvm/mmu.c:5912 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:769 [inline] kvm_put_kvm+0x30a/0xa90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:806 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:817 __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: 0033:0x7f923a1b2c9b RSP: 002b:00007fff4dd28eb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000014 RCX: 00007f923a1b2c9b RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000013 RBP: 00007f923a314960 R08: 0000000000000000 R09: 00007f923a3171c8 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000183a3d R13: 00007fff4dd28fb0 R14: 00007f923a312f60 R15: 0000000000000032 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.267-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+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 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: 4620 Comm: systemd-journal Not tainted 4.14.267-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a1652040 task.stack: ffff8880a1658000 RIP: 0033:0x7f8f4992a475 RSP: 002b:00007ffc2218c090 EFLAGS: 00000202 RAX: 00007f8f46ee96c8 RBX: 000000000012e6c8 RCX: 000000000012e6c8 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000561a85eb5120 RBP: 0000561a85eb4e80 R08: 0000000000000058 R09: 0000561a85eb5120 R10: 001a75472c31c336 R11: 00007f8f46c2c8b0 R12: 0000000000000001 R13: 00007ffc2218c118 R14: 0000000000000001 R15: 00007ffc2218c090 FS: 00007f8f49c3c8c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f46c2c000 CR3: 00000000a166b000 CR4: 00000000003426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400