syzbot


INFO: task hung in migrate_pages

Status: upstream: reported on 2023/12/27 03:46
Reported-by: syzbot+ca5cea833eef2d386860@syzkaller.appspotmail.com
First crash: 132d, last: 85d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in migrate_pages mm 14 1304d 1428d 0/26 auto-closed as invalid on 2021/01/09 03:04
linux-6.1 INFO: task hung in migrate_pages 1 211d 211d 0/3 auto-obsoleted due to no activity on 2024/01/17 09:52
linux-6.1 INFO: task hung in migrate_pages (2) 1 48d 48d 0/3 upstream: reported on 2024/03/20 12:05
upstream INFO: task hung in migrate_pages (2) mm 70 880d 907d 0/26 auto-closed as invalid on 2022/04/08 00:51
upstream INFO: task hung in migrate_pages (3) fs mm 10 436d 651d 0/26 auto-obsoleted due to no activity on 2023/05/27 13:42

Sample crash report:
INFO: task kcompactd0:30 blocked for more than 143 seconds.
      Not tainted 5.15.148-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kcompactd0      state:D stack:24800 pid:   30 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 io_schedule+0x88/0x100 kernel/sched/core.c:8484
 wait_on_page_bit_common+0xa13/0x1180 mm/filemap.c:1356
 lock_page include/linux/pagemap.h:625 [inline]
 __unmap_and_move mm/migrate.c:990 [inline]
 unmap_and_move mm/migrate.c:1214 [inline]
 migrate_pages+0xbef/0x3470 mm/migrate.c:1491
 compact_zone+0x1ddb/0x4330 mm/compaction.c:2424
 proactive_compact_node mm/compaction.c:2678 [inline]
 kcompactd+0x19a3/0x2910 mm/compaction.c:2988
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f220 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by udevd/2963:
 #0: ffff88801b7bd118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff888147329468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070
2 locks held by getty/3261:
 #0: ffff888024696098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bae2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz-executor.1/3542:
 #0: ffff8880b9a39718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9a27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x53d/0x810 kernel/sched/psi.c:891
 #2: ffff8880b9a27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:104 [inline]
 #2: ffff8880b9a27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: enqueue_task+0x2fe/0x3a0 kernel/sched/core.c:1973
2 locks held by kworker/u4:1/24517:
1 lock held by syz-executor.2/29313:
2 locks held by udevd/29387:
 #0: ffff88801b7b8918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff88801b796468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365
1 lock held by syz-executor.4/581:
 #0: ffff88801b7bd118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
1 lock held by syz-executor.0/613:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3556 Comm: syz-executor.3 Not tainted 5.15.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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+0x7b/0x290 mm/kasan/generic.c:189
Code: 00 00 00 00 fc ff df 4f 8d 34 1a 4c 89 f5 4c 29 cd 48 83 fd 10 7f 26 48 85 ed 0f 84 3a 01 00 00 49 f7 d2 49 01 da 41 80 39 00 <0f> 85 c4 01 00 00 49 ff c1 49 ff c2 75 ee e9 1d 01 00 00 45 89 cf
RSP: 0018:ffffc90002e87950 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffffffff1bc73d5 RCX: ffffffff81e1cc76
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8de39ea8
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1bc73d5
R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000001
R13: ffff888016ce0030 R14: fffffbfff1bc73d6 R15: dffffc0000000000
FS:  0000555556469480(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc099610000 CR3: 000000005d0f3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 cpu_online include/linux/cpumask.h:895 [inline]
 trace_writeback_dirty_inode include/trace/events/writeback.h:141 [inline]
 __mark_inode_dirty+0x346/0xd60 fs/fs-writeback.c:2466
 generic_update_time+0x1cb/0x1e0 fs/inode.c:1817
 inode_update_time fs/inode.c:1830 [inline]
 file_update_time+0x3eb/0x460 fs/inode.c:2019
 pipe_write+0x13ca/0x1b60 fs/pipe.c:598
 call_write_iter include/linux/fs.h:2146 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacf/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fd238144aef
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 80 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c 81 02 00 48
RSP: 002b:00007fff4b78b300 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000003501 RCX: 00007fd238144aef
RDX: 000000000000000c RSI: 00007fff4b78b3f0 RDI: 00000000000000f8
RBP: 00007fff4b78b38c R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 00000000002e7078 R14: 00000000002e6fbe R15: 0000000000000001
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/12 13:47 linux-5.15.y 6139f2a02fe0 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in migrate_pages
2024/02/02 10:29 linux-5.15.y 6139f2a02fe0 d61103fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in migrate_pages
2023/12/28 14:45 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in migrate_pages
2023/12/27 03:45 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in migrate_pages
* Struck through repros no longer work on HEAD.