syzbot

INFO: task kcompactd0:1651 blocked for more than 143 seconds.
      Not tainted 5.10.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kcompactd0      state:D stack:27584 pid: 1651 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3774 [inline]
 __schedule+0x92c/0xcb0 kernel/sched/core.c:4523
 schedule+0x14b/0x200 kernel/sched/core.c:4601
 io_schedule+0x86/0xf0 kernel/sched/core.c:6295
 wait_on_page_bit_common+0xa84/0xfc0 mm/filemap.c:1273
 lock_page include/linux/pagemap.h:611 [inline]
 __unmap_and_move+0x859/0xbf0 mm/migrate.c:1047
 unmap_and_move+0x2cd/0x10d0 mm/migrate.c:1197
 migrate_pages+0x41e/0xf70 mm/migrate.c:1453
 compact_zone+0x2c49/0x3ac0 mm/compaction.c:2314
 kcompactd_do_work mm/compaction.c:2724 [inline]
 kcompactd+0x70f/0x2530 mm/compaction.c:2819
 kthread+0x36b/0x390 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Showing all locks held in the system:
1 lock held by systemd/1:
1 lock held by khungtaskd/1647:
 #0: ffffffff8bae6840 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
3 locks held by kswapd0/2182:
1 lock held by kswapd1/2183:
2 locks held by systemd-journal/4869:
2 locks held by systemd-udevd/4894:
1 lock held by systemd-timesyn/4977:
2 locks held by in:imklog/8147:
2 locks held by cron/8130:
2 locks held by agetty/8166:
 #0: ffff88801bc8b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:266
 #1: ffffc90000f5c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1b40 drivers/tty/n_tty.c:2156
2 locks held by agetty/8168:
 #0: ffff888021fd8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:266
 #1: ffffc90000fa82e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1b40 drivers/tty/n_tty.c:2156
2 locks held by syz-fuzzer/8461:
3 locks held by syz-fuzzer/8464:
2 locks held by syz-fuzzer/8473:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1647 Comm: khungtaskd Not tainted 5.10.0-rc3-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+0x137/0x1be lib/dump_stack.c:118
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 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+0xcb0/0xcf0 kernel/hung_task.c:294
 kthread+0x36b/0x390 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8464 Comm: syz-fuzzer Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:match_held_lock+0x13/0x190 kernel/locking/lockdep.c:4889
Code: 05 6e 33 c5 76 00 00 00 00 eb b5 e8 87 fc ff ff 0f 1f 80 00 00 00 00 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <bb> 01 00 00 00 48 39 77 10 74 52 81 7f 20 00 00 10 00 72 47 48 8b
RSP: 0000:ffffc900012aee98 EFLAGS: 00000082
RAX: aec0e4274bec3b00 RBX: 0000000000000002 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8bae67a0 RDI: ffff8880181c5820
RBP: ffff8880181c5820 R08: dffffc0000000000 R09: fffffbfff19dc17e
R10: fffffbfff19dc17e R11: 0000000000000000 R12: 0000000000000002
R13: ffff8880181c4ec0 R14: 00000000ffffffff R15: ffffffff8bae67a0
FS:  000000c00003ee90(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fee25926303 CR3: 0000000013814000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __lock_is_held kernel/locking/lockdep.c:5184 [inline]
 lock_is_held_type+0x81/0x140 kernel/locking/lockdep.c:5475
 lock_is_held include/linux/lockdep.h:271 [inline]
 rcu_read_lock_sched_held+0x41/0xb0 kernel/rcu/update.c:123
 trace_lock_acquire+0x6b/0x180 include/trace/events/lock.h:13
 lock_acquire+0x39/0x5e0 kernel/locking/lockdep.c:5407
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:248
 rcu_read_lock include/linux/rcupdate.h:641 [inline]
 page_evictable+0x23/0x290 mm/internal.h:83
 move_pages_to_lru+0x22f/0x14c0 mm/vmscan.c:1855
 shrink_inactive_list+0x38a/0x910 mm/vmscan.c:1965
 shrink_list mm/vmscan.c:2170 [inline]
 shrink_lruvec+0x409/0x950 mm/vmscan.c:2465
 shrink_node_memcgs+0x323/0x6d0 mm/vmscan.c:2653
 shrink_node+0xc48/0x1ad0 mm/vmscan.c:2770
 shrink_zones+0x414/0x8d0 mm/vmscan.c:2973
 do_try_to_free_pages+0x205/0xa20 mm/vmscan.c:3028
 try_to_free_pages+0x324/0xb00 mm/vmscan.c:3267
 __perform_reclaim mm/page_alloc.c:4330 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4351 [inline]
 __alloc_pages_slowpath+0xf1d/0x23c0 mm/page_alloc.c:4755
 __alloc_pages_nodemask+0x31f/0x4f0 mm/page_alloc.c:4965
 alloc_pages include/linux/gfp.h:547 [inline]
 __page_cache_alloc+0x79/0x1d0 mm/filemap.c:977
 pagecache_get_page+0x85f/0xf80 mm/filemap.c:1828
 filemap_fault+0x1840/0x2560 mm/filemap.c:2725
 ext4_filemap_fault+0x82/0xa0 fs/ext4/inode.c:6192
 __do_fault+0x139/0x3b0 mm/memory.c:3612
 do_read_fault+0x5db/0xaa0 mm/memory.c:4006
 do_fault mm/memory.c:4134 [inline]
 handle_pte_fault mm/memory.c:4374 [inline]
 __handle_mm_fault mm/memory.c:4509 [inline]
 handle_mm_fault+0x183c/0x2590 mm/memory.c:4607
 do_user_addr_fault+0x4ca/0xa40 arch/x86/mm/fault.c:1372
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0xa1/0x1e0 arch/x86/mm/fault.c:1485
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583
RIP: 0033:0x79e5e3
Code: Unable to access opcode bytes at RIP 0x79e5b9.
RSP: 002b:000000c003c48ff8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000ea53c0 RCX: 0000000000000002
RDX: 0000000000f30b00 RSI: 0000000000000000 RDI: 0000000000b4c9a0
RBP: 000000c003c49028 R08: 0000000000879d60 R09: 0000000000000001
R10: 000000c006a6b0e0 R11: ffffffffffffffff R12: 000000000000010f
R13: 000000000000010e R14: 0000000000000200 R15: 0000000000000200