syzbot


INFO: task hung in __unmap_and_move (4)

Status: upstream: reported C repro on 2022/12/29 09:48
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+b7ad168b779385f8cd58@syzkaller.appspotmail.com
First crash: 600d, last: 45d
Cause bisection: failed (error log, bisect log)
  
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly mm report (Nov 2023) 0 (1) 2023/11/15 03:00
[syzbot] Monthly mm report (Jun 2023) 0 (1) 2023/06/07 22:37
[syzbot] INFO: task hung in __unmap_and_move (4) 3 (4) 2022/12/30 00:55
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __unmap_and_move (2) mm 7 1012d 1089d 0/26 auto-closed as invalid on 2021/10/10 14:18
upstream INFO: task hung in __unmap_and_move mm 1 1256d 1256d 0/26 auto-closed as invalid on 2021/02/08 10:09
upstream INFO: task hung in __unmap_and_move (3) mm 19 866d 916d 0/26 closed as invalid on 2022/02/07 18:59
Fix bisection attempts (12)
Created Duration User Patch Repo Result
2024/03/05 20:10 4h42m bisect fix upstream job log (0) log
2024/01/15 09:12 1h57m bisect fix upstream job log (0) log
2023/12/13 01:03 2h25m bisect fix upstream job log (0) log
2023/11/11 05:01 1h47m bisect fix upstream job log (0) log
2023/10/12 00:49 2h20m bisect fix upstream job log (0) log
2023/08/21 05:08 1h46m bisect fix upstream job log (0) log
2023/07/17 00:30 1h46m bisect fix upstream job log (0) log
2023/06/03 02:06 31m bisect fix upstream job log (0) log
2023/05/04 01:26 30m bisect fix upstream job log (0) log
2023/04/02 16:08 31m bisect fix upstream job log (0) log
2023/03/03 15:36 31m bisect fix upstream job log (0) log
2023/02/01 07:05 30m bisect fix upstream job log (0) log

Sample crash report:
INFO: task kcompactd1:32 blocked for more than 143 seconds.
      Not tainted 6.1.0-syzkaller-14594-g72a85e2b0a1e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kcompactd1      state:D stack:26360 pid:32    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x9d1/0xe40 kernel/sched/core.c:6555
 schedule+0xcb/0x190 kernel/sched/core.c:6631
 io_schedule+0x83/0x100 kernel/sched/core.c:8811
 folio_wait_bit_common+0x8ca/0x1390 mm/filemap.c:1297
 folio_lock include/linux/pagemap.h:938 [inline]
 __unmap_and_move+0x835/0x12a0 mm/migrate.c:1040
 unmap_and_move+0x28f/0xd80 mm/migrate.c:1194
 migrate_pages+0x50f/0x14d0 mm/migrate.c:1477
 compact_zone+0x2893/0x37a0 mm/compaction.c:2413
 proactive_compact_node mm/compaction.c:2665 [inline]
 kcompactd+0x1b46/0x2750 mm/compaction.c:2975
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d523910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d524110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
 #0: ffffffff8d523740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by kswapd0/81:
3 locks held by kswapd1/84:
1 lock held by klogd/4412:
3 locks held by dhcpcd/4635:
2 locks held by getty/4744:
 #0: ffff88802d6f3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177
2 locks held by syz-executor387/5109:
2 locks held by kworker/u4:0/5111:
 #0: ffff888012879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
 #1: ffffc90003f4fd00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
2 locks held by dhcpcd/5117:

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-syzkaller-14594-g72a85e2b0a1e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e3/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x19b/0x3e0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xcd5/0xd20 kernel/hung_task.c:377
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4635 Comm: dhcpcd Not tainted 6.1.0-syzkaller-14594-g72a85e2b0a1e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x84/0x2e0 mm/kasan/generic.c:189
Code: da 4d 89 d6 4d 29 ce 49 83 fe 10 7f 30 4d 85 f6 0f 84 8e 01 00 00 4c 89 cb 4c 29 d3 66 2e 0f 1f 84 00 00 00 00 00 41 80 39 00 <0f> 85 e7 01 00 00 49 ff c1 48 ff c3 75 ee e9 67 01 00 00 44 89 cd
RSP: 0000:ffffc9000359e788 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff816cc01b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8eb01da8
RBP: 000000000001ffff R08: dffffc0000000000 R09: fffffbfff1d603b5
R10: fffffbfff1d603b6 R11: 1ffffffff1d603b5 R12: dffffc0000000000
R13: ffffffff81c45785 R14: 0000000000000001 R15: 1ffff920006b3d08
FS:  00007f8f1abe3740(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f505f46d8b7 CR3: 000000001f195000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:444 [inline]
 cpu_online include/linux/cpumask.h:1030 [inline]
 trace_lock_release+0x5b/0x220 include/trace/events/lock.h:69
 lock_release+0x81/0x870 kernel/locking/lockdep.c:5679
 rcu_read_unlock include/linux/rcupdate.h:797 [inline]
 folio_evictable+0x1df/0x2d0 mm/internal.h:140
 move_folios_to_lru+0x324/0x25c0 mm/vmscan.c:2413
 shrink_inactive_list+0x60b/0xca0 mm/vmscan.c:2529
 shrink_list mm/vmscan.c:2767 [inline]
 shrink_lruvec+0x449/0xc50 mm/vmscan.c:5951
 shrink_node_memcgs+0x35c/0x780 mm/vmscan.c:6138
 shrink_node+0x299/0x1050 mm/vmscan.c:6169
 shrink_zones+0x4fb/0xc40 mm/vmscan.c:6407
 do_try_to_free_pages+0x215/0xcd0 mm/vmscan.c:6469
 try_to_free_pages+0x3e8/0xc60 mm/vmscan.c:6704
 __perform_reclaim mm/page_alloc.c:4750 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4772 [inline]
 __alloc_pages_slowpath+0xd5c/0x2120 mm/page_alloc.c:5178
 __alloc_pages+0x3d4/0x560 mm/page_alloc.c:5562
 folio_alloc+0x1a/0x50 mm/mempolicy.c:2296
 filemap_alloc_folio+0xca/0x2c0 mm/filemap.c:972
 page_cache_ra_unbounded+0x212/0x820 mm/readahead.c:248
 do_sync_mmap_readahead+0x786/0x950 mm/filemap.c:3062
 filemap_fault+0x38d/0x1060 mm/filemap.c:3154
 __do_fault+0x136/0x4f0 mm/memory.c:4163
 do_read_fault mm/memory.c:4514 [inline]
 do_fault mm/memory.c:4643 [inline]
 handle_pte_fault mm/memory.c:4931 [inline]
 __handle_mm_fault mm/memory.c:5073 [inline]
 handle_mm_fault+0x2076/0x26c0 mm/memory.c:5219
 do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428
 handle_page_fault arch/x86/mm/fault.c:1519 [inline]
 exc_page_fault+0x7a/0x120 arch/x86/mm/fault.c:1575
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x56359ff3a260
Code: Unable to access opcode bytes at 0x56359ff3a236.
RSP: 002b:00007fff59b49a78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000007d0 RCX: 000000000cdc2932
RDX: 0000000000000510 RSI: 0000000000000001 RDI: 00000000000007d0
RBP: 0000000000000510 R08: 000000001dc81186 R09: 0000000000000010
R10: 00007fff59b6c0b8 R11: 0000000000020822 R12: 00005635a0cbafd0
R13: 000056359ff50ee1 R14: 00005635a0da0a90 R15: 0000000000000001
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/25 09:38 upstream 72a85e2b0a1e 9da18ae8 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in __unmap_and_move
2022/10/31 22:23 upstream b229b6ca5abb 2a71366b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in __unmap_and_move
2022/10/02 09:27 upstream b357fd1c2afc feb56351 .config console log report info [disk image] [vmlinux] ci-upstream-kasan-gce-smack-root INFO: task hung in __unmap_and_move
2022/08/28 09:42 upstream 10d4879f9ef0 07177916 .config console log report info ci-upstream-kasan-gce-smack-root INFO: task hung in __unmap_and_move
* Struck through repros no longer work on HEAD.