INFO: task syz-executor.2:11474 blocked for more than 143 seconds.
      Not tainted 5.4.0-rc6 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28016 11474   8755 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3384 [inline]
 __schedule+0x94f/0x1e70 kernel/sched/core.c:4069
 schedule+0xd9/0x260 kernel/sched/core.c:4136
 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871
 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/0x14c0 kernel/workqueue.c:2826
 nbd_start_device_ioctl drivers/block/nbd.c:1299 [inline]
 __nbd_ioctl drivers/block/nbd.c:1374 [inline]
 nbd_ioctl+0xb2e/0xc44 drivers/block/nbd.c:1414
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0xedb/0x1c20 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: 0033:0x45a219
Code: 48 8d 7c 24 30 48 39 3b 75 ad 48 89 23 eb a8 cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 59 48 83 ec 48 48 89 6c 24 40 48 <8d> 6c 24 40 48 8b 59 20 48 85 db 75 49 48 8b 74 24 60 8b 4c 24 68
RSP: 002b:00007f7d362aac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045a219
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7d362ab6d4
R13: 00000000004c3de9 R14: 00000000004d8188 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1070:
 #0: ffffffff88fab340 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5337
2 locks held by rsyslogd/8620:
 #0: ffff8880a113eb60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
 #1: ffff8880aa401818 (&(&parent->list_lock)->rlock){-.-.}, at: syslog_print kernel/printk/printk.c:1364 [inline]
 #1: ffff8880aa401818 (&(&parent->list_lock)->rlock){-.-.}, at: do_syslog kernel/printk/printk.c:1529 [inline]
 #1: ffff8880aa401818 (&(&parent->list_lock)->rlock){-.-.}, at: do_syslog+0x68e/0x1820 kernel/printk/printk.c:1503
2 locks held by getty/8710:
 #0: ffff8880a9509090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8711:
 #0: ffff88809963e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8712:
 #0: ffff888091c5e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8713:
 #0: ffff888094032090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8714:
 #0: ffff8880a7d14090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8715:
 #0: ffff888096dbd090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/8716:
 #0: ffff8880a514c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by kworker/u5:1/11332:
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline]
 #0: ffff88809ab45928 ((wq_completion)knbd2-recv){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240
 #1: ffff888059fa7dc0 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1070 Comm: khungtaskd Not tainted 5.4.0-rc6 #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
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:67
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffff8880ae809ac8 EFLAGS: 00000202
RAX: 1ffff1101230be00 RBX: ffffed101230be80 RCX: 0000000000000000
RDX: 0000000000000080 RSI: 0000000000000000 RDI: ffffed101230be80
RBP: ffff8880ae809ae0 R08: ffffffff88e7a180 R09: ffffed101230be00
R10: ffffed101230be00 R11: ffff88809185f000 R12: 0000000000000400
R13: 00000000ffffffff R14: ffff8880ae809b88 R15: ffff88808ec1a780
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 000000008e86d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 ksize mm/slab_common.c:1776 [inline]
 ksize+0x47/0x60 mm/slab_common.c:1749
 __alloc_skb+0x124/0x5e0 net/core/skbuff.c:216
 alloc_skb include/linux/skbuff.h:1049 [inline]
 new_skb+0x28/0x1d0 drivers/block/aoe/aoecmd.c:67
 aoecmd_cfg_pkts drivers/block/aoe/aoecmd.c:426 [inline]
 aoecmd_cfg+0x1b5/0x640 drivers/block/aoe/aoecmd.c:1372
 discover_timer+0x4e/0x60 drivers/block/aoe/aoemain.c:24
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: f8 bc 5e fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 04 9b 58 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d f4 9a 58 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 7e 22 11 fa e8 19
RSP: 0018:ffffffff88e07ce8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11e63bf RBX: ffffffff88e7a180 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88e7aa14
RBP: ffffffff88e07d18 R08: ffffffff88e7a180 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff89c66a00 R14: 0000000000000000 R15: 0000000000000000
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x3b7/0x6e0 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355
 rest_init+0x245/0x37b init/main.c:451
 arch_call_rest_init+0xe/0x1b
 start_kernel+0x904/0x943 init/main.c:784
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241