INFO: task syz-executor.2:17057 blocked for more than 143 seconds.
      Not tainted 5.3.0+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28216 17057  10394 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3384 [inline]
 __schedule+0x76e/0x17d0 kernel/sched/core.c:4056
 schedule+0xd9/0x260 kernel/sched/core.c:4123
 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1869
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
 flush_workqueue+0x40f/0x14b0 kernel/workqueue.c:2826
 nbd_start_device_ioctl drivers/block/nbd.c:1254 [inline]
 __nbd_ioctl drivers/block/nbd.c:1329 [inline]
 nbd_ioctl+0xb32/0xc50 drivers/block/nbd.c:1369
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0xedb/0x1c1a block/ioctl.c:606
 block_ioctl+0xee/0x130 fs/block_dev.c:1954
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: 24 18 0f b6 05 0f f7 3b 01 3c 01 76 0a 48 8b 6c 24 18 48 83 c4 20 c3 75 07 e8 63 08 fd ff 0f 0b c6 05 f1 f6 3b 01 01 48 b8 00 <00> 00 00 00 00 f0 7f 48 89 04 24 e8 a7 dd fa ff f2 0f 10 44 24 08
RSP: 002b:00007ff9bfbd9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004598e9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff9bfbda6d4
R13: 00000000004c31c9 R14: 00000000004d6978 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 1063 Comm: khungtaskd Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0x9d0/0xef0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60