INFO: task kcompactd0:1174 blocked for more than 143 seconds.
      Not tainted 5.8.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kcompactd0      D28752  1174      2 0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 io_schedule+0xb5/0x120 kernel/sched/core.c:6296
 wait_on_page_bit_common+0x52c/0xca0 mm/filemap.c:1191
 lock_page include/linux/pagemap.h:548 [inline]
 __unmap_and_move mm/migrate.c:1046 [inline]
 unmap_and_move mm/migrate.c:1196 [inline]
 migrate_pages+0x741/0x3210 mm/migrate.c:1457
 compact_zone+0x1b0e/0x39d0 mm/compaction.c:2315
 kcompactd_do_work+0x2bd/0x770 mm/compaction.c:2725
 kcompactd+0x25d/0xd00 mm/compaction.c:2820
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Showing all locks held in the system:
1 lock held by khungtaskd/1132:
 #0: ffffffff89bd6380 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825
1 lock held by kswapd1/1691:
2 locks held by systemd-journal/3903:
2 locks held by systemd-udevd/3905:
1 lock held by rsyslogd/6498:
1 lock held by in:imklog/6515:
1 lock held by cron/6513:
2 locks held by syz-fuzzer/6839:
2 locks held by syz-fuzzer/6840:
2 locks held by syz-fuzzer/6850:
5 locks held by kworker/u4:6/32596:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1132 Comm: khungtaskd Not tainted 5.8.0-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:unwind_get_return_address+0x70/0x90 arch/x86/kernel/unwind_orc.c:318
Code: 75 32 48 8b 7b 48 e8 0f f6 19 00 85 c0 74 d3 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 75 18 48 8b 43 48 <5b> 5d c3 e8 c8 e2 80 00 eb a8 48 89 ef e8 ce e2 80 00 eb c4 48 89
RSP: 0000:ffffc90000d2f818 EFLAGS: 00000246
RAX: ffffffff81b435df RBX: ffffc90000d2f830 RCX: 0000000000000000
RDX: 1ffff920001a5f0f RSI: 0000000000000001 RDI: ffffffff81b435df
RBP: ffffc90000d2f878 R08: ffffffff8b267d54 R09: ffffffff8b267d58
R10: 000000000007201e R11: 0000000000000001 R12: ffffc90000d2f8e8
R13: 0000000000000000 R14: ffff8880a963e300 R15: 00000000000000e0
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb8d2d8122d CR3: 00000000a1d53000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 slab_post_alloc_hook mm/slab.h:518 [inline]
 slab_alloc_node mm/slab.c:3254 [inline]
 kmem_cache_alloc_node+0x136/0x3f0 mm/slab.c:3574
 __alloc_skb+0x71/0x550 net/core/skbuff.c:198
 alloc_skb include/linux/skbuff.h:1085 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:501 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:558 [inline]
 nsim_dev_trap_report_work+0x2b2/0xbe0 drivers/net/netdevsim/dev.c:599
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294