syzbot


INFO: task hung in migrate_pages

Status: auto-obsoleted due to no activity on 2024/01/17 09:52
Reported-by: syzbot+da6bca601b02839466f1@syzkaller.appspotmail.com
First crash: 430d, last: 430d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in migrate_pages mm 14 1524d 1647d 0/28 auto-closed as invalid on 2021/01/09 03:04
linux-5.15 INFO: task hung in migrate_pages 4 304d 352d 0/3 auto-obsoleted due to no activity on 2024/05/22 13:48
linux-6.1 INFO: task hung in migrate_pages (2) 1 267d 267d 0/3 auto-obsoleted due to no activity on 2024/06/28 12:05
upstream INFO: task hung in migrate_pages (2) mm 70 1100d 1127d 0/28 auto-closed as invalid on 2022/04/08 00:51
upstream INFO: task hung in migrate_pages (3) fs mm 10 655d 871d 0/28 auto-obsoleted due to no activity on 2023/05/27 13:42

Sample crash report:
INFO: task kcompactd0:31 blocked for more than 143 seconds.
      Not tainted 6.1.56-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kcompactd0      state:D stack:24544 pid:31    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6554
 schedule+0xbf/0x180 kernel/sched/core.c:6630
 io_schedule+0x88/0x100 kernel/sched/core.c:8782
 folio_wait_bit_common+0x878/0x1290 mm/filemap.c:1296
 __unmap_and_move mm/migrate.c:1032 [inline]
 unmap_and_move mm/migrate.c:1186 [inline]
 migrate_pages+0xaa7/0x4070 mm/migrate.c:1463
 compact_zone+0x2aef/0x41e0 mm/compaction.c:2414
 proactive_compact_node mm/compaction.c:2666 [inline]
 kcompactd+0x1862/0x28e0 mm/compaction.c:2976
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
INFO: task syz-executor.2:9153 blocked for more than 143 seconds.
      Not tainted 6.1.56-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:26936 pid:9153  ppid:469    flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6554
 schedule+0xbf/0x180 kernel/sched/core.c:6630
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6689
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 blkdev_put+0x100/0x750 block/bdev.c:911
 blkdev_close+0x56/0x80 block/fops.c:514
 __fput+0x3b7/0x890 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1a39a7cae9
RSP: 002b:00007f1a3a8260c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f1a39b9bf80 RCX: 00007f1a39a7cae9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f1a39ac847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f1a39b9bf80 R15: 00007ffd6feb6578
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12a170 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12a970 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 #0: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #0: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6493
2 locks held by kworker/u4:2/38:
 #0: ffff8880b9939e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffff8880b9927788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a3/0x770 kernel/sched/psi.c:988
2 locks held by getty/3305:
 #0: ffff888027f7e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
4 locks held by kworker/u4:24/4053:
 #0: ffff8880b9939e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffff8880b9927788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:1000
 #2: ffff888098554d40 (&wdev->mtx){+.+.}-{3:3}, at: sdata_lock net/mac80211/ieee80211_i.h:1114 [inline]
 #2: ffff888098554d40 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_ibss_work+0xa0/0x1480 net/mac80211/ibss.c:1680
 #3: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 #3: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
 #3: ffffffff8d129fa0 (rcu_read_lock){....}-{1:2}, at: ieee80211_sta_active_ibss+0xb1/0x310 net/mac80211/ibss.c:654
1 lock held by udevd/11308:
 #0: ffff88801f3574c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:813
1 lock held by syz-executor.2/9153:
 #0: ffff88801f3574c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x750 block/bdev.c:911
1 lock held by syz-executor.2/9256:
 #0: ffff88801f3574c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:813
1 lock held by syz-executor.2/9321:
 #0: ffff88801f3574c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:813

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.56-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 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+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 38 Comm: kworker/u4:2 Not tainted 6.1.56-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: bat_events batadv_nc_worker
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:__lock_acquire+0xcc9/0x1f80 kernel/locking/lockdep.c:5018
Code: 63 9c 24 80 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 20 82 49 90 be 08 00 00 00 e8 11 4f 77 00 48 bf 00 00 00 00 00 fc ff df <48> 0f a3 1d df 36 df 0e 0f 83 40 08 00 00 49 8d 9d d0 0a 00 00 48
RSP: 0018:ffffc90000af79a0 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 000000000000002b RCX: ffffffff816a4b2f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000
RBP: ffff8880166dc6b0 R08: dffffc0000000000 R09: fffffbfff2093045
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880166dc658
R13: ffff8880166dbb80 R14: ffff8880166dc6d0 R15: 1ffff11002cdb8da
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00a908948 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
 rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
 rcu_read_lock include/linux/rcupdate.h:747 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xe8/0x610 net/batman-adv/network-coding.c:719
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/09 09:51 linux-6.1.y ecda77b46871 5e837c76 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in migrate_pages
* Struck through repros no longer work on HEAD.