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Subject[syzbot] INFO: task hung in migrate_pages (2)
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Hello,

syzbot found the following issue on:

HEAD commit: 5833291ab6de Merge tag 'pci-v5.16-fixes-1' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14b04e6eb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d7259f0deb293aa
dashboard link: https://syzkaller.appspot.com/bug?extid=67c846f7c9b8278e8471
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+67c846f7c9b8278e8471@syzkaller.appspotmail.com

INFO: task kcompactd0:30 blocked for more than 143 seconds.
Not tainted 5.15.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kcompactd0 state:D stack:28032 pid: 30 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4969 [inline]
__schedule+0xa9a/0x4940 kernel/sched/core.c:6250
schedule+0xd2/0x260 kernel/sched/core.c:6323
io_schedule+0xee/0x170 kernel/sched/core.c:8368
folio_wait_bit_common+0x4f2/0xa60 mm/filemap.c:1371
lock_page include/linux/pagemap.h:747 [inline]
__unmap_and_move mm/migrate.c:980 [inline]
unmap_and_move mm/migrate.c:1204 [inline]
migrate_pages+0xa5a/0x3810 mm/migrate.c:1481
compact_zone+0x1abb/0x3860 mm/compaction.c:2399
kcompactd_do_work+0x2c9/0x730 mm/compaction.c:2839
kcompactd+0x86b/0xf30 mm/compaction.c:2941
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>

Showing all locks held in the system:
1 lock held by systemd/1:
#0: ffff88801725c160 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:838 [inline]
#0: ffff88801725c160 (mapping.invalidate_lock){++++}-{3:3}, at: page_cache_ra_unbounded+0x1b3/0x940 mm/readahead.c:194
1 lock held by khungtaskd/27:
#0: ffffffff8b983a20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
1 lock held by kswapd1/99:
2 locks held by kworker/u4:4/942:
#0: ffff8880b9d39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478
#1: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a6/0x490 kernel/sched/psi.c:880
2 locks held by in:imklog/6199:
1 lock held by cron/6194:
#0: ffffffff8baa8140 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4585 [inline]
#0: ffffffff8baa8140 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4609 [inline]
#0: ffffffff8baa8140 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa1e/0x20d0 mm/page_alloc.c:5007
1 lock held by syz-executor.5/12840:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:295
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 942 Comm: kworker/u4:4 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:update_load_avg+0xa/0x1830 kernel/sched/fair.c:3804
Code: e9 b3 fa ff ff 48 8b 7c 24 28 e8 a1 bd 6a 00 e9 38 f7 ff ff e8 97 bd 6a 00 e9 4e f7 ff ff 66 90 48 b8 00 00 00 00 00 fc ff df <41> 57 41 56 41 55 41 54 55 48 89 f5 53 48 89 fb 48 81 c7 c4 01 00
RSP: 0018:ffffc90004adfb10 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8880178d5790 RCX: 1ffff110035fa014
RDX: 0000000000000000 RSI: ffff88801afd0080 RDI: ffff8880b9d39b40
RBP: ffff88801afd0080 R08: ffff88801afd0090 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880178d5798
R13: ffff8880b9d39b40 R14: dffffc0000000000 R15: 000006eb640c7135
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3fc0028020 CR3: 000000000b68e000 CR4: 0000000000350ee0
Call Trace:
<TASK>
put_prev_entity+0x272/0x5b0 kernel/sched/fair.c:4541
pick_next_task_fair+0x69c/0xe00 kernel/sched/fair.c:7308
__pick_next_task kernel/sched/core.c:5590 [inline]
pick_next_task kernel/sched/core.c:5662 [inline]
__schedule+0x3e8/0x4940 kernel/sched/core.c:6214
preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6416
__cond_resched+0x13/0x20 kernel/sched/core.c:8129
_cond_resched include/linux/sched.h:2017 [inline]
process_one_work+0xaf4/0x1690 kernel/workqueue.c:2324
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
----------------
Code disassembly (best guess):
0: e9 b3 fa ff ff jmpq 0xfffffab8
5: 48 8b 7c 24 28 mov 0x28(%rsp),%rdi
a: e8 a1 bd 6a 00 callq 0x6abdb0
f: e9 38 f7 ff ff jmpq 0xfffff74c
14: e8 97 bd 6a 00 callq 0x6abdb0
19: e9 4e f7 ff ff jmpq 0xfffff76c
1e: 66 90 xchg %ax,%ax
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 41 57 push %r15 <-- trapping instruction
2c: 41 56 push %r14
2e: 41 55 push %r13
30: 41 54 push %r12
32: 55 push %rbp
33: 48 89 f5 mov %rsi,%rbp
36: 53 push %rbx
37: 48 89 fb mov %rdi,%rbx
3a: 48 rex.W
3b: 81 .byte 0x81
3c: c7 .byte 0xc7
3d: c4 .byte 0xc4
3e: 01 00 add %eax,(%rax)


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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